RS Aggarwal Class 7 Mathematics Third Chapter Decimals Exercise 3B Solution

RS Aggarwal Class 7 Mathematics Third Chapter Decimals Exercise 3B Solution

EXERCISE 3B

Add:

(1) 16, 8.7, 0.94, 6.8 and 7.77

= 16.00 + 08.70 + 00.94 + 06.80 + 07.77

= 40.21

(2) 18.6, 206.37, 8.008, 26.4 and 6.9

= 018.600 + 206.370 + 008.008 + 026.400 + 006.900

= 266.278

(3) 63.5, 9.7, 0.8, 26.66 and 12.17

= 63.50 + 09.70 + 00.80 + 26.66 + 12.17

= 112.83

(4) 17.4, 86.39, 9.435, 8.8 and 0.06

= 14.400 + 86.390 + 09.435 + 08.800 + 00.060

= 122.085

(5) 26.9, 19.74, 231.769 and 0.048

= 026.900 + 019.740 + 231.769 + 000.048

= 278.457

(6) 23.8, 8.94, 0.078 and 214.6

= 023.800 + 008.940 + 000.078 + 214.600

= 247.418

(7) 6.606, 66.6, 666, 0.066, 0.66

= 006.606 + 066.600 + 666.000 + 000.066 + 000.660

= 739.932

(8) 9.09, 0.909, 99.9, 9.99, 0.099

= 009.090 + 000.909 + 099.900 + 009.990 + 000.099

= 119.988

Subtract:

(9) 14.79 from 72.43

= 72.43 – 14.79

= 57.64

(10) 36.74 from 52.6

= 52.60 – 36.74

= 15.86

(11) 13.876 from 22

= 22.000 – 13.876

= 8.124

(12) 15.079 from 24.16

= 24.160 – 15.079

= 9.081

(13) 0.68 from 1.007

= 1.007 – 0.680

= 0.327

(14) 0.4678 from 5.05

= 5.0500 – 0.4678

= 4.5822

(15) 2.5307 from 8

= 8.0000 – 2.5307

= 5.4693

(16) 6.732 from 9.001

= 9.001 – 6.732

= 2.269

(17) Take out 5.746 from 9.1.

= 9.100 – 5.746

= 3.354

(18) What is to be added to 63.58 to get 92?

Solution: 92.00 – 63.58 = 28.42

(19) What is to be subtracted from 8.1 to get 0.813?

Solution: 8.100 – 0.813 = 7.287

(20) By how much should 32.67 be increased to get 60.1?

Solution: 60.10 – 32.67 = 27.43

(21) By how much should 74.3 be decreased to get 26.87?

Solution: 74.30 – 26.87 = 47.43

(22) Rohit purchased a notebook for Rs 23.75 , a pencil for Rs 2.85 and pen for Rs 15.90. He gave a 50-rupee note to the shopkeeper. What amount did he get back?

Solution: 50.00 – (23.75 + 02.85 + 15.90)

= 50.00 – 42.50

= 7.50

Therefore, Rohit get back 7.50 rupees.