Mental Math Class 5 Worksheet – Decimals
Mental Math Class 5 Worksheet Chapter Number. Here in this page we have given total 25 Questions Set with Solution for Students.
(Q1) Find the decimals form of 5/100?
Solution:
We know,
The number of digits on the right side of decimal is equal to no. of zeroes in denominator of fraction
∴ 5/100 = 0.05
(Q2) Find the decimal from of 523/1000?
Solution:
We know, No. of digits on the right side of decimal point is equal to no. of zeroes in denominator of fraction.
∴ 523/1000 = 0.523
(Q3) Find Decimal form of 52/10?
Solution:
We know, No. of digits on the right side of decimal point is equal to no. of zeroes in denominator of fraction.
52/10 = 5.2
(Q4) Find simplest form of 0.035?
Solution:
There are 3 digits on the right side of decimal point.
∴ The denominator of a fraction contains 3 zeroes
∴ 0.035 = 35/1000
(Q5) Find simplest fractional form of 0.38?
Solution:
Here, there are 2 digits on the right side of decimal point.
∴ The denominator contains 2 zeroes in fraction.
∴ 0.38 = 38/100
By simplifying 38/100 = 19/50
(Q6) Find decimal form of 62/50
Solution:
To make decimal form of 62/50, we have to make
Denominator —- 10, 100, 1000 — soon
∴ We make denominator 100
∴ 62/50 = 62×2/50×2 = 124/100
∴ 124/100 = 1.24
(Q7) Find place value of 2 in 49.026?
Solution:
Here, 2 is in ‘Hundredth’ place in 49.026
∴ Place value of 2 is 2/100 or two-hundredth
(Q8) Find place value of 8 in 36.038?
Solution:
Here, 8 is in ‘Thousandth’ place in 36.038.
∴ Place value of 8 is 8/1000 or 8-thousandth
(Q9) Arrange the decimal numbers in ‘Descending Order’
8, 0.08, 0.8, 0.008, 80, 800
Solution:
Descending order depends upon no. of digits are on right side of decimal point.
If, No. of digits are less then that number is greater.
Descending order is
∴ 80, 8, 0.8, 0.08, 0.008
(Q10) Arrange the decimal numbers in ‘Ascending order’
40, 4, 0.004, 0.04
Solution:
No. of digits on right side of decimal point is more, then the number is ‘small’.
∴ Ascending order is
0.004, 0.04, 4, 40
(Q11) Express 40 rupees and 78 paise in decimal fraction.
Solution:
We know, 1 rupees = 100 paise
78 paise = 78/100 rupees
∴ 40 rupees & 78 paise = 40.78 rupees
(Q12) Find the value 9 + 2/100 + 3/1000
Solution:
Here, 2/100 contains 2 zeroes in denominator
Hence, 2/100 = 0.02 Also,
3/1000 contains 3 zero
∴ 3/1000 = 0.003
∴ 9 + 2/100 + 3/1000 = 9.025
(Q13) Find 3.05 + 0.45
Solution:
For, addition we have to arrange decimal point of both in equal position
(3.05+0.45) = 3.50
∴ 3.05 + 0.45 = 3.50
(Q14) Find 9.52 – 2.21
Solution:
For subtraction, we have to arrange decimal pt of both in equal position.
∴ 9.52 – 2.21 = 7.31
(Q15) Find 4.8 × 10
Solution:
When we multiply decimal number to 100, we have to move decimal point by 2 digit on right side.
4.8 × 100 = 480
(Q16) Find 3.2 × 2.3
Solution:
There are 2 decimal points in 3.2×2.3
∴ We 1st multiply both normally. And when we get answer we move 2 digits on left side to give decimal point.
32×23 = 736
∴ 3.2 × 2.3 = 7.36
(Q17) Express 973 cm into metre?
Solution:
We know, 1m = 100 cm
∴ 1 cm = 1/100 m
∴ 973m = 973/100 m
∴ 973 cm = 9.73 m
(Q18) How much should be added to 37.15 to get 55.00?
Solution:
Let we add ‘x’ to 37.15 to get 55.00
∴ x + 37.15 = 55.00
∴ x = 55.00 – 37.15
x = 17.85
∴ 17.85 added in 37.15 to get 55
(Q19) How much should be subtracted from 38.25 to get 24.75?
Solution:
Let, ‘x’ is subtracted from 38.25 to get 24.75
∴ 38.25 = x = 24.75
∴ x = 38.25 – 24.75
x = 13.5
∴ 13.5 subtracted from 38.25 to get 24.75.
(Q20) Find product of 0.3 × 0.003
Solution:
Here 1st we count No. of decimal points.
∴ There are 4 decimal points.
∴ Answer contains 4 decimal points.
∴ We first multiply normally by value.
3×3 = 9
∴ 0.009
(Q21) Find 6 tenth + 9 hundredth?
Solution:
We know, 6 tenth’s à 6/10 = 0.6
Also, 9-hundredt = 9/100 = 0.09
∴ 0.6 + 0.09
= 0.69
∴ 6 tenth + 9 hundredth = 0.69
(Q22) Find 33.25 + 50.647
Solution:
We have to add 33.25 + 50.647
∴ 33.25 + 50.647 = 83.897
(Q23) Find 89.432 – 30.54
Solution:
We have to subtract 89.432 – 30.57
89.432 – 30.54 = 58.892
(Q24) 3 pens cost is Rs 75.75. Find cost of 1 pen?
Solution:
Cost of 3 pens is Rs 75.75
∴ Cost of 1 pen = 75.75/3
∴ Cost of 1 pen = Rs 25.25
(Q25) Each side of square is 9.45 cm. Find perimeter of square?
Solution:
We know perimeter of square = 4 × side
Side of square is 9.45 cm
∴ Perimeter of square = 4 × 9.45 cm
Perimeter of square = 37.8 cm