Selina Class 6 ICSE Solutions – Page 4

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 4 Place Value

August 11, 2022May 24, 2018 by Prasanna

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 4 Place Value

Selina Publishers Concise Mathematics Class 6 ICSE Solutions Chapter 4 Place Value

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Mathematics. You can download the Selina Concise Mathematics ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Mathematics for Class 6 ICSE Solutions all questions are solved and explained by expert mathematic teachers as per ICSE board guidelines.

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Place Value Exercise 4A – Selina Concise Mathematics Class 6 ICSE Solutions

Question 1.
Fill in the blanks :
(i) In 20 kg, the unit is ………….., which is taken …………. times.
(ii) In 80 m, the unit is …………., which is taken …………. times.
(iii) If a unit cm (centimetre) is taken 5 times, the corresponding quantity is …………….
(iv) If a unit km (kilometre) is taken 24 times, the corresponding quantity is ……………
(v)

Number	Numeral	Numeration
53	………….	……….
………	9	…………
240	…………..	………..

Solution:
(i) In 20 kg, the unit is kg, which is taken 20 times.
(ii) In 80 m, the unit is m, which is taken 80 times.
(iii) If a unit cm (centi metre) is taken 5 times, the corresponding quantity is 5 cm.
(iv) If a unit km (kilo metre) is taken 24 times, the corresponding quantity is 24 km.
(v)

Number	Numeral	Numeration
53	53	fifty three
9	9	Nine
240	240	two hundred forty

Question 2.
Fill in the blanks :
(i) In 24,673 ; the place value of 6 is ………..
(ii) In 8,039 ; the place value of 8 is …………..
(iii) In 3,25,648; the local value of 5 is ……………
(iv) In 6,439 ; the local value of 6 is ……….
Solution:
(i) In 24,673 ; the place value of 6 is 6 x 100 = 600.
(ii) In 8, 039 ; the place value of 8 is 8 x 1000 = 8000.
(iii) In 3, 25, 648 ; the local value of 5 is 5 x 1000 = 5000.
(iv) In 6, 439 ; the local value of 6 is 6 x 1000 = 6000.

Question 3.
Find the difference between the place values of 3 and 5 in the number 3945.
Solution:
Place values of 3 in 3945 is 3000 and 5 is 5
Difference between them = 3000 – 5 = 2995

Question 4.
In the number 40562
(i) the local value of 5 = …………..
(ii) the place value of 6 = ………..
(iii) the sum of the place value of 5 and the place value of 6 = …………
Solution:
(i) the local value of 5 = 500 and its local value is 5.
(ii) the place value of 6 = 60
(iii) the sum of the place value of 5 and the place value of 6 = 500 + 60 = 560

Question 5.
Read and write the following numbers in words and also in expanded form :
(i) 35,000 = …………
(ii) 76,000 = ……………
(iii) 6,23,000 = ………….
(iv) 40,075 = …………….
(v) 50,004 = ………..
Solution:
(i) 35,000 = Thirty five thousands = 3 x 10000 + 5 x 1000
(ii) 76,000 = Seventy six thousands = 7 x 10000 + 6 x 1000
(iii) 6,23,000 = Six lakhs twenty three thousands = 6 x 100000 + 23 x 1000
(iv) 40,075 = Forty thousands seventy five = 4 x 10000 + 75 x 10 + 5
(v) 50,004 = Fifty thousands four = 5 x 10000 + 4

Question 6.
Find the difference in the place values of two sevens in the number 8, 72, 574.
Solution:
In 8,72,574, the first 7 occurs at ten thousand place.
=> Its place value = 70000
=> The second 7 occurs at ten’s place.
Its place value = 70
The difference of the two place values of 7 = 70000 – 70 = 69930

Place Value Exercise 4B – Selina Concise Mathematics Class 6 ICSE Solutions

Question 1.
Fill in the blanks :
(i) 999 + 1 = …………
(ii) 10,000 – 1 = …………
(iii) 10 coins – one coin = …………
(iv) ₹ 99 + ₹ 1 = ………..
(v) 10,000 boys – 1 boy = ………..
(vi) 1000 toys – 1 toy = ……….
Solution:
(i) 999 + 1 = 1,000
(ii) 10,000 – 1 =9,999
(iii) 10 coins – one coin = 9 coins
(iv) ₹ 99 + ₹ 1 = ₹ 100
(v) 10,000 boys – 1 boy = 9,999 boys
(vi) 1000 toys – 1 toy = 999 toys

Question 2.
Would the number of students in your school be a 3-digit number or a 4-digit number or a 5-digit number ?
Solution:
Note : This answer will vary from school to school.
Since, the total strength of M.G.N. Public school is 5410.
Hence, It is a 4-digit number.

Question 3.
Write the smallest number which is just more than 9, 99, 999.
Solution:
Given number = 9, 99, 999
Smallest number which is more than 1 is = 9, 99, 999 + 1 = 10, 00, 000

Question 4.
Starting from the greatest 5-digit number, write the previous five numbers in descending order.
Solution:
Greatest digit number = 99, 999
Next four numbers in descending order
99, 999 > 99998 > 99997 > 99996 > 99995

Question 5.
Starting from the smallest 7-digit number, write the next four numbers in ascending order.
Solution:
Smallest 7-digit number = 10, 00, 000
Next four numbers in ascending order
10,00,001 < 1000002 < 1000003 < 1000004 <1000005

Question 6.
How many numbers lie between the largest 3-digit number and the smallest 4-digit number ?
Solution:
Largest 3-digit number = 999
Smallest 4-digit number = 1000
Required number = (1000 – 999) = 1

Question 7.
How many 5-digit numbers are there in all?
Solution:
Largest number of 5-digits = 99999 Largest number of 4-digits = 9999
Required number=99999 – 9999 = 90,000
So, 90,000 numbers are there in all.

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System

August 11, 2022May 24, 2018 by Prasanna

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System (Consolidating the Sense of Numberness)

Selina Publishers Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System (Consolidating the Sense of Numberness)

ICSE Solutions Selina ICSE Solutions ML Aggarwal Solutions

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics

IMPORTANT POINTS

Place-Value (Local Value) : The place value (Local-value) of a digit depends upon the position, it occupies in the number:
For example :
In the number 6453
the place value of 6 is 6 thousand = 6 x 1000 = 6000
the place value of 4 is 4 hundred = 4 x 100 = 400
the place value of 5 is 5 ten = 5 x 10 = 50
the place value of 3 is 3 one = 3 x 1 = 3
Face-Value (True-Value) : Each digit in a number has a fixed value, regardless to its position in the number
For Example :
In the above number 6453
Face value of 6 is 6, 4 is 4, 5 is 5 and 3 is 3
An Abstract Number : Which does not refer to any particular unit e.g., 3, 5, 9.
A Concrete Number : Which refers to particular unit e.g., 3 boys, 5 girls, 9 rooms etc.
The smallest (least) one digit Number is 1.
The largest (greatest) one digit number is 9.

Number System Exercise 1A – Selina Concise Mathematics Class 6 ICSE Solutions

Question 1.
Which is greater ?
(i) 537 or 98
(ii) 2428 or 529
(iii) 2, 59, 467 or 10, 35, 729
Solution:
(i) 537 or 98
Since 537 is three digit number and 98 is two digit number.
Hence 537 > 98 and 537 is greater
(ii) 2428 or 529
Since 2498 is four digit number and 529 is three digit number.
2498 > 529 ; 2498 is greater
(iii) 2, 59, 467 or 10, 35, 729
Since 10, 35, 729 is seven digit number and 2, 59, 467 is six digit number
10, 35, 729 > 2, 59, 467 ; 10, 35, 729 is greater

Question 2.
Which is smaller ?
(i) 428 or 437
(ii) 2497 or 2597
(iii) 3297 or 3596
Solution:
(i) 428 or 437
We observe that both the numbers are of three-digits.
And at the leftmost, both the number have same digit i.e. 4. But at the second place from the left, the first, number has 2 and the second number has 3.
Since 2 < 3
437 is greater
(ii) 2497 or 2597
We observe that both the numbers are of four digits.
And at the leftmost, both the numbers have same digit i.e. 2. But at the second place from the left, the first number has 4 and the second number has 5.
Since 4 < 5
2597 is greater
(iii) 3297 or 3596
We observe that both the numbers are of four digits.
And at the leftmost, both the numbers have same digit i.e. 2. But at the second place from the left, the first number has 4 and the second number has 5.
Since 4 < 5
3596 is greater

Question 3.
Which is greater ?
(i) 45293 or 45427
(ii) 380362 or 381007
(iii) 63520 or 63250
Solution:
(i) 45293 or 45427
We observe that both the numbers are of 5-digits.
And at the digits at leftmost and second place from the left are same.
But the digits at the third place from the left are different, the first number has 2 and the second number has 4.
Since 2 < 4
45427 is greater
(ii) 380362 or 381007
We observe that both the numbers are of 6-digits.
And at the digits at leftmost and second place from the left are same.
But the digits at the third place from the left are different, the first number has 0 and the second number has 1.
Since 0 < 1
381007 is greater
(iii) 63520 or 63250
We observe that both the numbers are of 5-digits.
And at the digits at leftmost and second place from the left are same.
But the digits at the third place from the left are different, the first number has 5 and the second number has 2.
Since 5 < 2
63520 is greater

Question 4.
By making a suitable chart, compare:
(i) 540276 and 369998
(ii) 6983245 and 6893254
Solution:
(i) 540276 and 369998

5	4	0	2	7	6
3	6	9	9	9	8

Clearly, both the numbers have equal number of digits i.e. 6
And at the leftmost, the first number has 5 and the second number has 3.
Since 5 > 3
540276 is greater.
(ii) 6983245 and 6893254

6	9	8	3	2	4	5
6	8	9	3	2	5	4

Clearly, both the numbers have equal number of digits i.e. 7
And at the leftmost, both have the same digit i.e. 6
And at the second place from the left, the first number has 9 and the second number has 8.
Since 9 > 8
6983245 is greater.

Question 5.
Compare the numbers written in the following table by writing them in ascending order:

	5	4	3	2	9	7	2
2	3	1	0	6	2	9	3
	5	2	2	3	7	9	1
2	3	1	8	2	6	3	4
5	4	3	4	4	7	8	2

Solution:
The given number in ascending order are as :
54344782 > 243182634 > 23106293 > 5432972> 5223791

5	4	3	4	4	7	8	2
2	3	1	8	2	6	3	4
2	3	1	0	6	2	9	3
	5	4	3	2	9	7	2
	5	2	2	3	7	9	1

Question 6.
Use table form to compare the numbers in descending order : 5,43,287; 54,82,900; 27,32,940; 43,877 ; 78,396 and 4,999
Solution:
The given numbers in descending order are as :

			4	9	9	9
		4	3	8	7	7
		7	8	3	9	6
	5	4	3	2	8	7
2	7	3	2	9	4	0
5	4	8	2	9	0	0

4, 999 < 43, 877 < 78, 396 < 5, 43, 287 < 27, 32, 940 < 54, 82, 900

Question 7.
Find the smallest and the greatest numbers in each case given below:
(i) 983, 5754, 84 and 5942
(ii) 32849, 53628, 5499 and 54909.
Solution:
(i) 983, 5754, 84 ahd 5942
Since 84 has the least number of digits.
84 is the least smallest whereas 5754 and 5942 have the maximum number of digits.
Out of 5754 and 5942, 5942 is greater.
5942 is the greatest and 84 is the smallest.
(ii) 32849, 53628, 5499 and 54909.
Since 5499 has the least number of digits.
5499 is the smallest
Whereas 54909 and 53628 have the maximum number of digits. Out of 54909 and 53628, 54909 is greater.
54909 is the greatest and 5499 is the smallest

Question 8.
Form the greatest and the smallest 4 digit numbers using the given digits without repetition
(i) 3, 7, 2 and 5
(ii) 6, 1, 4 and 9
(iii) 7, 0, 4 and 2
(iv) 1, 8, 5 and 3
(v) 9, 6, 0 and 7
Solution:
(i) The given digits are 3, 7, 2 and 5
(a) The greatest 4-digit number = 7532
(b) and the smallest 4-digit number = 2357
(ii) The digits are given : 6, 1, 4 and 9
(a) The greatest 4-digit number = 9641
(b) and the smallest 4-digit number = 1469
(iii) The digits are given 7, 0, 4 and 2
(a) The greatest 4-digit number = 7420
(b) The smallest 4-digit number = 2047
(iv) the digits are given 1, 8, 5 and 3
(a) The greatest 4-digit number = 8531
(b) and the smallest 4-digit number =1358
(v) The digits are given 9, 6, 0 and 7
(a) The greatest 4-digit number = 9760
(b) and the smallest 4-digit number = 6079

Question 9.
Form the greatest and the smallest 3-digit numbers using any three different digits with the condition that digit 6 is always at the unit (one’s) place.
Solution:
The condition for 3-digit number of three different digits is that 6 is at the ones place
The greatest 3-digit number will be 986 and the smallest 3-digit number will be 106

Question 10.
Form the greatest and the smallest 4-digit number using any four different digits with the condition that digit 5 is always at ten’s place.
Solution:
The condition for 4-digit number of four different digits is that 5 is always at its tens place
The greatest 4-digit number will be 9857 and the smallest 4-digit number will be 1052

Question 11.
Fill in the blanks :
(i) The largest number of 5-digit is …………… and the smallest number of 6-digit is …………….
(ii) The difference between the smallest number of four digits and the largest number of three digits = …………. – ………….. = …………..
(iii) The sum (addition) of the smallest number of three digit and the largest number of two digit = ………… + …………= ………….
(iv) On adding one to the largest five digit number, we get ……………. which is the smallest ……………… digit number.
(v) On subtracting one from the smallest four digit number, we get ……………… which is the ……………. three digit number.
Solution:
(i) The largest number of 5-digit is 99999 and the smallest number of 6-digit is 100000
(ii) The difference between the smallest number of four digits and the largest number of three digits = 1000 – 999 = 1
(iii) The sum (addition) of the smallest number of three digit and the largest number of two digit = 100 + 99 = 199
(iv) On adding one to the largest five digit number, we get 100000 which is the smallest six digit number.
(v) On subtracting one from the smallest four digit number, we get 999 which is the greatest three digit number.

Question 12.
Form the largest number with the digits 2, 3, 5, 9, 6 and 0 without repetition of digits.
Solution:
Largest number = 9, 65, 320.

Question 13.
Write the smallest and the greatest numbers of 4 digits without repetition of any digit.
Solution:
Smallest 4 digits number = 1023
Greatest number of 4 digits = 9876

Question 14.
Find the greatest and the smallest five digit numbers with 8 in hundred’s place and with all the digits different.
Solution:
Greatest 5-digit number = 97865 and smallest 5-digit number = 10823

Question 15.
Find the sum of the largest and the smallest four-digit numbers:
Solution:
Largest four-digits number = 9,999
Smallest four digits number = 1,000
Sum of the above = 9, 999 + 1,000 = 10,999.

Question 16.
Find the difference between the smallest and the greatest six-digits numbers.
Solution:
Greatest six-digits number = 9, 99, 999
Smallest six-digits number = 1,00,000
Difference between greatest and smallest = 9, 99, 999 – 1, 00, 000 = 8, 99, 999

Question 17.
(i) How many four digit numbers are there between 999 and 3000 ?
(ii) How many four digit numbers are there between 99 and 3000 ?
Solution:
(i) Four digit numbers between 999 and 3000 = 2999 – 999 = 2000
(ii) Four digit numbers between 99 and 3000 = 2999 – 999 = 2000

Question 18.
How many four digit numbers are there between 500 and 3000 ?
Solution:
Four digits numbers between 99 and 3000 = 2999 – 999 = 2000

Question 19.
Write all the possible three digit numbers using the digits 3, 6 and 8 only; if the repetition of digits is not allowed.
Solution:
All the three digits number using 3, 6, and 8 when repetition is not allowed, can be :
368, 386, 638, 683, 836, 863.

Question 20.
Make the greatest and the smallest 4-digit numbers using the digits 5, 4, 7 and 9 (without repeating the digits) and with the condition that:
(i) 7 is at unit’s place.
(ii) 9 is at ten’s place
(iii) 4 is at hundred’s place
Solution:
(i) 7 is at unit’s place
The smallest 4-digit number using the digits 5, 4, 7 and 9, and keeping 7 at unit’s place = 4597
The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 7 at unit’s place = 9547
(ii) 9 is at ten’s place
The smallest 4-digit number using the digits 5, 4, 7 and 9 and keeping 9 at ten’s place = 4597
The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 9 at ten’s place = 7594
(iii) 4 is at hundred’s place
The smallest 4-digit number using the digits 5, 4, 7 and 9 and keeping 4 at hundred’s place = 5479
The greatest 4-digit number using the digits 5, 4, 7 and 9 and keeping 4 at hundred’s place = 9475

Number System Exercise 1B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Population of a city was 3, 54, 976 in the year 2014. In the year 2015, it was found to be increased by 68, 438. What was the population of the city at the end of the year 2015?
Solution:
Population of a city in 2014 = 3,54, 976
Population increased in 2015 = 68, 438
Total population at the end of the year 2015 = 3, 54, 976 + 68, 438 = 423414
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 1

Question 2.
A = 7,43,000 and B = 8,00,100. Which is greater A or B ? And, by how much?
Solution:
A = 7,43,000
B = 8,00,100
B is greater than A. (B > A)
Because = B – A
Since A = 7, 43, 000 and B = 800,100 and both the numbers have 6 digits.
And at the leftmost, the first number has 7 and the second number has 8.
Since 8 > 7
800, 600 > 7,43,000 (B > A)
B is greater than A by = 800, 100 – 7, 43, 000 = 57, 100
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 2

Question 3.
A small and thin notebook has 56 pages. How many total number of pages will 5326 such note-books have?
Solution:
Number of pages in one notebook = 56 pages
Number of pages in 5326 notebooks = 5326 x 56 = 298256 pages
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 3

Question 4.
The number of sheets of paper available for making notebooks is 75,000. Each sheet makes 8 pages of a notebook. Each notebook contains 200 pages. How many notebooks can be made from the available paper ?
Solution:
Number of sheets available = 75, 000
Number of pages obtained from one sheet = 8
Total number of pages obtained = 8 x 75, 000 = 6, 00, 000
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 4

Question 5.
Add 1, 76, 209; 4, 50, 923 and 44, 83, 947
Solution:
1, 76, 209 + 4, 50, 923 + 44, 83, 947
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 5
Adding these values, we get = 51, 11, 079

Question 6.
A cricket player has so far scored 7, 849 runs in test matches. He wishes to complete 10, 000 runs ; how many more runs does he need ?
Solution:
Score of cricket player = 7, 849 runs
Total scores he wish to complete = 10,000
Runs required = 10, 000 – 7, 849 = 2151
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 6

Question 7.
In an election two candidates A and B are the only contestants. If candidate A scored 9, 32, 567 votes and candidates B scored 9, 00, 235 votes, by how much margin did A win or loose the election ?
Solution:
Scores of candidate A = 9,32,567
Scores of candidate B = 9,00,235
Candidate A win the election By margin = 9,32,567 – 9,00,235 = 32,332 scores
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 7

Question 8.
Find the difference between the largest and the smallest number that can be written using the digits 5, 1, 6,3 and 2 without repeating any digit.
Solution:
The digits given are = 5, 1, 6, 3 and 2
The largest 5-digit number that can be formed using the digits 5, 1, 6, 3 and 2 = 65321
The smallest 5-digit number that can be formed using the digits 5, 1,6, 37and 2 =12356
Difference between 65321 and 12356
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 8
= 65321 – 12356 = 52,965

Question 9.
A machine manufactures 5,782 screws every day. How many screws will it manufacture in the month of April ?
Solution:
Number of screws in one day = 5, 782
Number of days in April = 30 days
Number of screws in April = 5, 782 x 30 = 1,73,460
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 9

Question 10.
A man had ₹ 1, 57, 184 with him. He placed an order for purchasing 80 articles at 125 each. How much money will remain with him after the purchase ?
Solution:
Money in hand = ₹ 1, 57, 184
Number of articles purchased = 80
Cost of one article = ₹ 125
Cost of 80 articles = ₹ 80 x 125 = ₹ 10,000
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 10

Question 11.
A student multiplied 8,035 by 87 instead of multiplying by 78. By how much was his answer greater than or less than the correct answer ?
Solution:
Correct answer = 8,035 x 87 = 6,99,045
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 11

Question 12.
Mohani has 30 m cloth and she wants to make some shirts for her son. If each shirt requires 2 m 30 cm cloth, how many shirts, in all, can be made and how much length of cloth will be lefft ?
Solution:
Total length of cloth available = 30 m or 30 x 100 = 3000 cm
Shirt made by using 2m 30cm (230 cm) cloth = 1
Shirts made by using 30 m cloth = \(\frac { 1 }{ 230 }\) x 3000 = 13.04 = 13 shirts
Cloth required to make 13 shirts = 230 x 13 = 2990 cm or 29 m 90 cm
Hence, remaining cloth = 30 m – 29 m = 1m

Question 13.
The weight of a box is 4 kg 800 gm. What is the total weight of 150 boxes?>
Solution:
Weight of one box = 4 kg 800 gm
Total weight of 150 boxes = 4 kg 800 g x 150 = 720 kg
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 12

Question 14.
The distance between two places A and B is 3 km 760 m. A boy travels A to B and then B to A every day. How much distance does he travel in 8 days?
Solution:
Distance between two places = 3 km 760 m 3760 m
Distance among A to B and B to A = 2 x 3760 m = 7520 m
In 8 days he travelled = 7520 x 8 = 60160 m or 60 km 160 m

Question 15.
An oil-tin contains 6 litre 60 ml oil. How many identical bottles can the oil fill, if capacity of each bottle is 30 ml ?
Solution:
Oil contained in a tin = 6 litre 60 ml = 6 x 1000 + 60 = 6060 ml
Capacity of each bottle = 30 ml
No. of bottled can be filled with 30 ml oil = 6060 ÷ 30 = 202 bottles
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 13

Question 16.
The scale receipt of a company in a certain year was ₹ 83, 73, 540. In the following year, it was decreased by ₹ 7, 84, 670.
(i) What was the sale receipt of the company during second year?
(ii) What was the total sale receipt of the company during these two years?
Solution:
Sale receipt of the company during first year = ₹ 83,73,540
Sale decreased in second year = ₹ 7,84,670
(i) The sale receipt of the company during second year = ₹ 83,73,540 – ₹ 7,84,670
Selina Concise Mathematics Class 6 ICSE Solutions Chapter 1 Number System image - 14
(ii) Total sale receipt of the company during these two years = ₹ 83, 73, 540 + ₹ 75, 88, 870 = ₹ 1, 59, 62, 410

Question 17.
A number exceeds 8, 59, 470 by 3, 00, 999. What is the number?
Solution:
First number = 8, 59, 470
Difference between second and first number = 3, 00, 999
Second number = 8, 59, 470 + 3, 00, 999 = 11, 60, 469

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Selina Concise Mathematics Class 6 ICSE Solutions Chapter 2 Estimation

August 11, 2022May 23, 2018 by Prasanna

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 2 Estimation

Selina Publishers Concise Mathematics Class 6 ICSE Solutions Chapter 2 Estimation

ICSE Solutions Selina ICSE Solutions ML Aggarwal Solutions

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics

Estimation Exercise 2A – Selina Concise Mathematics Class 6 ICSE Solutions

Question 1.
Round off each of the following to the nearest ten :
(i) 62
(ii) 265
(iii) 543
(iv) 8261
(v) 6294
(vi) 3008
(vii) 72326
Solution:
If the digit at ones place is less than 5, replace ones digit by 0, and keep the other digit as they are :
And if the digit at ones place is 5 or more than 5, increase tens digit by 1, and replace ones digit by 0.
(i) 62 – 60
(ii) 265 – 270
(iii) 543 – 540
(iv) 8261 – 8260
(v) 6294 – 6290
(vi) 3008-3010

Question 2.
Round off each of the following to the nearest hundred :
(i) 748
(ii) 784
(iii) 2667
(iv) 5432
(v) 6388
(vi) 59237
Solution:
If the tens digit is less than 5, replace each one of tens and once digits by 0 and keep the other digits as they are :
(i) 748 – 700
(ii) 784 – 800
(iii) 2667 – 2700
(iv) 5432 – 5400
(v) 6388 – 6400
(vi) 59237 – 59200

Question 3.
Round off each of the following to the nearest thousand :
(i) 6475
(ii) 6732
(iii) 5352
(iv) 32568
(v) 9248
(vi) 83294
Solution:
If the tens digit is 5 or more than 5, increase the hundreds digit by 1 and replace each of tens digit and ones digit by 0.
(i) 6475 – 6000
(ii) 6732 – 7000
(iii) 25352 – 25000
(iv) 32568 – 33000
(v) 9248 – 9000
(vi) 83294 – 83000

Question 4.
Round off
(i) 578 to the nearest ten.
(ii) 578 to the nearest hundred.
(iii) 4327 to the nearest thousand.
(iv) 32974 to the nearest ten-thousand.
(v) 27487 to the nearest ten-thousand.
Solution:
(i) 578 – 580
(ii) 578 – 600
(iii) 4327 – 4000
(iv) 32974 – 30000
(v) 27487 – 30000

Question 5.
Round off each of the following to the nearest tens, hundreds and thousands.
(i) 864
(ii) 1249
(iii) 54, 547
(iv) 68, 076
(v) 56, 293
(vi) 7, 293
(vii) 89, 24, 379
Solution:
(i) 864 – 860
864 – 900
864 – 1000
(ii) 1249 – 1250
1249 – 1200
1249 – 1000
(iii) 54, 547 – 54550
54, 547 – 54500
54, 547 – 55000
(iv) 68, 076 – 68, 080
68, 076 – 68, 100
68, 076 – 68, 000
(v) 56, 293 – 56, 290
56, 293 – 56, 300
56, 293 – 56, 000
(vi) 7, 293 – 7290
7, 293 – 7, 300
7, 293 – 7000
(vii) 89, 24, 379 – 89, 24, 380
89, 24, 379 – 89, 24, 400
89, 24, 379 – 89, 24, 000

Question 6.
Round off the following to the nearest tens ;
(i) ₹ 562
(ii) 837 m
(iii) 545 cm
(iv) ₹ 27
Solution:
(i) ₹ 562
₹ 562 – ₹ 560
(ii) 837 m
837 – 840 m
(iii) 545 cm
545 – 550
(iv) ₹ 21
₹ 27 – ₹ 30

Question 7.
List all the numbers which can be round off to 30.
Solution:
The numbers that can be rounded off to 30 are:
26, 27, 28, 29, 31, 32, 33, 34

Question 8.
List all the numbers which can be rounded off to 50.
Solution:
The numbers that can be rounded off to 50 are:
46, 47, 48, 49, 51, 52, 53, 54

Question 9.
Write the smallest and the largest numbers which are rounded off to 80.
Solution:
The smallest number which is rounded off to 80 is 75
and the largest number which is rounded off to 80 is 84.

Question 10.
Write the smallest and the largest numbers which are rounded off to 130.
Solution:
The smallest number which is rounded off to 130 is 125
and The largest number which is rounded off to 130 is 134.

Estimation Exercise 2B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Estimate the sum of each pair of numbers to the nearest ten :
(i) 67 and 44
(ii) 34 and 87
(iii) 23 and 66
(iv) 78 and 18
(v) 96 and 55
(vi) 76 and 62
(vii) 457 and 175
(viii) 474 and 173
(ix) 527 and 267
Solution:
(i) 67 and 44
67 to the nearest ten 70 and, 44 to the nearest ten = 40
∴ Required sum (70 + 40) = 110
(ii) 34 and 87
34 to the nearest ten = 30 and, 87 to the nearest ten = 90
∴ Required sum = (30 + 90) = 120
(iii) 23 and 66
23 to the nearest ten = 20 and, 66 to the nearest ten = 70
∴ Required sum = (20 + 70) = 90
(iv) 78 and 18
78 to the nearest ten = 80 and, 18 to the nearest ten = 20
∴ Required sum = (80 + 20) = 100
(v) 96 and 55
96 to the nearest ten = 100 and, 55 to the nearest ten = 60
∴ Required sum = (100 + 60) = 160
(vi) 76 and 62
76 to the nearest ten = 80 and, 62 to the nearest ten = 60
∴ Required sum = (80 + 60) = 140
(vii) 457 and 175
457 to the nearest ten = 460 and, 175 to the nearest ten = 180
∴ Required sum = (460 + 180) = 640
(viii) 474 and 173
474 to the nearest ten = 470 and, 173 to the nearest ten = 170
∴ Required sum = (470 + 170) = 640
(ix) 527 and 267
527 to the nearest ten = 530 and, 267 to the nearest ten = 270
∴ Required sum = (530 + 270) = 800

Question 2.
Estimate the sum of each pair of numbers to the nearest hundred :
(i) 336 and 782
(ii) 546 and 342
(iii) 270 and 495
(iv) 4280 and 5295
(v) 4230 and 2410
(vi) 30047 and 39287
Solution:
(i) 336 and 782
336 to the nearest hundred = 300 and, 782 to the nearest hundred = 800
∴ Required sum = (300 + 800) = 1100
(ii) 546 and 342 and, 342 to the nearest hundred = 300
∴ Required sum = (500 + 300) = 800
(iii) 270 and 495
270 to the nearest hundred = 300 and, 495 to the nearest hundred = 500
∴ Required sum = (300 + 500) = 800
(iv) 4280 and 5295
4280 to the nearest hundred = 4300 and, 5295 to the nearest hundred = 5300
∴ Required sum = (4300 + 5300) = 9600
(v) 4230 and 2410
4230 to the nearest hundred = 4200 and, 2410 to the nearest hundred = 2400
∴ Required number = (4200 + 2400) = 6600
(vi) 30047 and 39287
30047 to the nearest hundred = 30000 and, 39287 to the nearest hundred = 39300
∴ Required sum = (30000 + 39300) = 69, 300

Question 3.
Estimate the sum of the following pair of numbers to the nearest thousand:
(i) 53826 and 36455
(ii) 56802 and 22475
Solution:
(i) 53826 and 36455
53826 to the nearest hundred = 54000 and, 36455 to the nearest hundred = 36000
∴ Required sum = (54000 + 36000) = 90000
(ii) 56802 and 22475
56802 to the nearest thousand = 57000 and, 22475 to the nearest thousand = 22000
∴ Required sum = (57000 + 22000) = 79000

Question 4.
Estimate the following differences correct to nearest ten :
(i) 82 – 27
(ii) 96 – 36
(iii) 508 – 248
Solution:
(i) 82 – 27
82 to the nearest ten = 80 and, 27 to the nearest ten = 30
∴ Required difference = (80 – 30) = 50
(ii) 96 – 36
96 to the nearest ten = 100 and, 36 to the nearest ten = 40
∴ Required difference = (100 – 40) = 60
(iii) 508 – 248
508 to the nearest ten = 510 and, 248 to the nearest ten = 250
∴ Required difference = (510 – 250) = 260

Question 5.
Estimate each difference to the nearest hundred :
(i) 769 – 314
(ii) 856 – 687
(iii) 6352 – 2086
Solution:
(i) 769 – 314
769 to the nearest hundred = 800 and, 314 to the nearest hundred = 300
∴ Required difference = (800 – 300) = 500
(ii) 856 – 687
856 to the nearest hundred = 900 and, 687 to the nearest hundred = 700
∴ Required difference = (900 – 700) = 200
(iii) 6352 – 2086
6352 to the nearest hundred = 6400 and, 2086 to the nearest hundred = 2100
∴ Required difference = (6400 – 2100) = 4300

Question 6.
Estimate each difference to the nearest thousand :
(i) 45974 – 38766
(ii) 76003 – 48399
Solution:
(i) 45974 – 38766
45974 to the nearest thousand = 46000 and, 38760 to the nearest thousand = 39000
∴ Required difference = (46000 – 39000) = 7000
(ii) 76003 – 48399
76003 to the nearest thousand = 76000 and, 48399 to the nearest thousand = 48000
∴ Required difference = (76000 – 48000) = 28000

Question 7.
Estimate each of the following products by rounding of each number to the nearest ten :
(i) 49 x 52
(ii) 63 x 38
(iii) 27 x 54
(iv) 53 x 85
(v) 74 x 67
(vi) 25 x 33
Solution:
(i) 49 x 52
49 to the nearest ten = 50 and, 52 to the nearest ten = 50
∴ Required product = (50 x 50) = 2500
(ii) 63 x 38
63 ta the nearest ten = 60 and, 38 to the nearest ten = 40
∴ Required product = (60 x 40) = 2400
(iii) 27 x 54
27 to the nearest ten = 30 and, 54 to the nearest ten = 50
∴ Required product = (30 x 50) = 1500
(iv) 53 x 85
53 to the nearest ten = 50 and, 85 to the nearest ten = 90
∴ Required product = (50 x 90) = 4500
(v) 74 x 67
74 to the nearest ten = 70 and, 67 to the nearest ten = 70
∴ Required product = (70 x 70) = 4900
(vi) 25 x 33
25 to the nearest ten = 30 and, 33 to the nearest ten = 30
∴ Required product = (30 x 30) = 900

Question 8.
Estimate each of the following products by rounding off each number to the nearest hundred :
(i) 477 x 213
(ii) 624 x 236
(iii) 333 x 247
(iv) 537 x 283
(v) 382 x 127
(vi) 427 x 328
Solution:
(i) 477 x 213
477 to the nearest hundred = 500 and, 213 to the nearest hundred = 200
∴ Required product = (500 x 200) = 100000
(ii) 624 x 236
624 to the nearest hundred = 600 and, 236 to the nearest hundred = 200
∴ Required product = (600 x 200) = 120000
(iii) 333 x 247
333 to the nearest hundred = 300 and, 247 to the nearest hundred = 200
∴ Required product = (300 x 200) = 60000
(iv) 537 x 283
537 to the nearest hundred = 500 and, 283 to the nearest hundred = 300
∴ Required product = (500 x 300) = 150000
(v) 382 x 127
382 to the nearest hundred = 400 and, 127 to the nearest hundred = 100
∴ Required product = (400 x 100) = 40000
(vi) 427 x 328
472 to the nearest hundred = 500 and, 328 to the nearest hundred = 300
∴ Required product = (500 x 300) = 150000

Question 9.
Estimate each of the following products by rounding off the first number correct to nearest ten and the other number correct to nearest hundred :
(i) 28 x 287
(ii) 432 x 128
(iii) 48 x 165
(iv) 72 x 258
(v) 83 x 664
(vi) 44 x 250
Solution:
(i) 28 x 287
28 to the nearest ten = 30 and, 287 to the nearest hundred = 300
∴ Required product = (30 x 300) = 9000
(ii) 432 x 128
432 to the nearest ten = 430 and, 128 to the nearest hundred = 100
∴ Required product = (430 x 100) = 43000
(iii) 48 x 165
48 to the nearest ten = 50 and, 165 to the nearest hundred = 200
∴ Required product = (50 x 200) = 10000
(iv) 72 x 258
72 to the nearest ten = 70 and, 258 to the nearest hundred = 300
∴ Required product = (70 x 300) = 21000
(v) 83 x 664
83 to the nearest ten = 80 and, 664 to the nearest hundred = 700
∴ Required product = (80 x 700) = 56000
(vi) 44 x 250
44 to the nearest ten = 40 and, 250 to the nearest hundred = 300
∴ Required product = (40 x 300) = 12000

Question 10.
Estimate each of the following quotients by converting each number to the nearest ten :
(i) 87 ÷ 28
(ii) 84 ÷ 23
(iii) 77 ÷ 22
(iv) 198 ÷ 24
(v) 355 ÷ 26
(vi) 444 ÷ 42
(vii) 843 ÷ 33
Solution:
(i) 87 ÷ 28
(87 ÷ 28) is (approximately to the nearest 10) equal to 90 ÷ 30 = 3
(ii) 84 ÷ 23
84 ÷ 23 is (approximately to the nearest 10) equal to 80 ÷ 20 = 4
(iii) 77 ÷ 22
77 ÷ 22 is (approximately to the nearest 10) equal to 80 ÷ 20 = 4
(iv) 198 ÷ 24
198 ÷ 24 is (approximately to the nearest 10) equal to 200 ÷ 20 = 10
(v) 355 ÷ 26
355 ÷ 26 is (approximately to the nearest 10) equal to 360 ÷ 30 = 12
(vi) 444 ÷ 42
444 ÷ 42 is (approximately to the nearest 10) equal to 440 ÷ 40 = 11
(vii) 843 ÷ 33
843 ÷ 33 is (approximately to the nearest 10) equal to 840 ÷ 30 = 28

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 3 Numbers in India and International System

August 11, 2022May 23, 2018 by Prasanna

Selina Concise Mathematics Class 6 ICSE Solutions Chapter 3 Numbers in India and International System (With Comparison)

Selina Publishers Concise Mathematics Class 6 ICSE Solutions Chapter 3 Numbers in India and International System (With Comparison)

ICSE Solutions Selina ICSE Solutions ML Aggarwal Solutions

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics

IMPORTANT POINTS

Place -Value (Local Value) : The place – value (Local-value) of a digit depends upon the position, it occupies in the number:
For example :
In the number 6453 the place value of 6 is 6 thousand = 6 x 1000 = 6000
the place value of 4 is 4 hundred = 4 x 100 = 400
the place value of 5 is 5 ten = 5 x 10 = 50
the place value of 3 is 3 one = 3 x 1=3
Face -Value (True-Value) : Each digit in a number has a fixed value, regardless to its position in the number
For Example :
In the above number 6453
Face of value of 6 is 6, 4 is 4, 5 is 5 and 3 is 3
An Abstract Number : Which does not refer to any particular unit e.g., 3, 5, 9.
A Concrete Number : Which refers to particular unit e.g., 3 boys, 5 girls, 9 rooms etc.
The smallest (least) one digit Number is 1.
The largest (greatest) one digit number is 9.

Numbers in India and International System Exercise 3 – Selina Concise Mathematics Class 6 ICSE Solutions

Question 1.
Write the following numerals using Indian System words or International system (as required in words) :
(i) 4, 35, 342 = …………..
(ii) 36, 71, 430 = …………..
(iii) 4, 28, 30, 004 = …………..
(iv) 75, 132, 684 = ……………
(v) 815, 906 = …………….
(vi) 5, 420, 700 = ……………..
Solution:
(i) 4, 35, 342 = four lakh, thirty five thousand, three hundred forty two
(ii) 36, 71, 430 = Thirty six lakh, seventy one thousand four hundred thirty
(iii) 4, 28, 30, 004 = four crore, twenty eight lakh, thirty thousand four
(iv) 75, 132, 684 = Seventy five million, one hundred thirty two thousand, six hundred eighty four
(v) 815, 906 = Eight hundred fifteen thousand, nine hundred six
(vi) 5, 420, 700 = Five million, four hundred twenty thousand, seven hundred

Question 2.
Write the following numbers, placing the commas, according to Indian system :
(i) 835629 = …………
(ii) 35640254 = …………
(iii) 2826040 = ………
Solution:
(i) 835629 = 8, 35, 629
(ii) 35640254 = 3, 56, 40, 254
(iii) 2826040 = 28, 26, 041

Question 3.
Write the following numbers, by placing the commas, according to International system :
(i) 6509820 = ………..
(ii) 428140584 = …………
(iii) 63560981 = ……….
Solution:
(i) 6509820 = 6, 509, 820
(ii) 428140584 = 428, 140, 584
(iii) 63560981 = 63, 560, 981

Question 4.
Fill in the blanks :
(i) Four lakh sixty seven thousand three hundred six.
= ……………… (In numeral form)
= …………… (In International System)
= ……………. (In International numeration)
(ii) Thirteen lakh forty five.
= ……………. (In numeral form)
= ……………. (In International System)
= ……………. (In International numerals)
Solution:
(i) Four lakh sixty seven thousand three hundred six
= 4, 67, 306
= 467, 306
= Four hundred sixty seven thousand three hundred six
(ii) Thirteen lakh forty five
= 13, 00, 45
= 130, 045
= One hundred thirty thousand forty five

Question 5.
Fill in the blanks :
(i) Six hundred four thousand eight hundred forty seven.
= ……………. (In numeral form)
= ……………. (In Indian System)
= ……………… (Number name in Indian System)
(ii) Two million three hundred ten thousand one hundred four
= …………….. (In numeral form)
= …………… (In Indian System)
= ……………. (In Indian numeration)
= …………….. (In international numerals)
Solution:
(i) Six hundred four thousand eight hundred forty seven
= 6, 04, 847
= 604, 847
= Six lakh four thousand eight hundred forty seven
(ii) Two million three hundred ten thousand one hundred four
= 2, 310, 104
= 23, 10, 104
= Twenty three lakh ten thousand one hundred four
= 2, 310, 104

Selina Class 6 Maths ICSE Solutions Physics Chemistry Biology Geography History & Civics