INTERNATIONAL INDIAN SCHOOL, AL JUBAIL

CLASS V SUBJECT: MATHEMATICS

CHAPTER # 7 DECIMALS (Part 3)

ADDITION AND SUBTRACTION OF DECIMALS

ADDITION OF DECIMALS

Exercise 7 F

Question No.1 (Do in textbook)

2. Add (Write in notebook)

a) 23.11 + 3.8

2 3 . 1 1
+ 3 . 8 0
2 6 . 9 1

b) 13.01 + 1.1 + 1.98

1 3 . 0 1
1 . 1 0
+ 1 . 9 8
1 6 . 0 9

c) 9 + 1.8

9 . 0
+ 1 . 8
1 0 . 8
d) 562.9 + 49.3

5 6 2 . 9
+ 4 9 . 3
6 1 2 . 2

e) 0.1 + 1 +11.40

0 . 1 0
1 . 0 0
+1 1 . 4 0
1 2 . 5 0

f) 162.1 + 16.21

1 6 2 . 1 0
+ 1 6 . 2 1
1 7 8 . 3 1

g) 9.85 + 0.61

9 . 8 5
+ 0 . 6 1
1 0 . 4 6
h) 17.01 + 18.1

1 7 . 0 1
+1 8 . 1 0
3 5 . 1 1

3. Compare using > , < or =

a) 2.5 + 3.09 5.95

2.5 + 3.09 = 5.59

5.9 < 5.95
2.5 + 3.09 < 5.95
b) 3 + 0.05 0.35

3 + 0.05 = 3.05
3.05 > 0.35
3 + 0.05 > 0.35

c) 10 + 0.01 10.01

10 + 0.01 = 10.01
10.01 = 10.01
10 + 0.01 = 10.01

d) 21.93 + 1.16 1.8 + 20.16

21.93 + 1.16 = 23.09

1.8 + 20.16 = 21.96
23.09 > 21.96
21.93 + 1.16 > 1.8 + 20.16
SUBTRACTION OF DECIMALS

Exercise 7 G (To be done in NB)

1. Subtract.

a) 9.32 – 4.16

9 . 3 2

-4 . 1 6

5 . 1 6

b) 18.43 – 9.26

1 8 . 4 3

- 9 . 2 6

9 . 1 7

c) 7 – 4.32

7 . 0 0

-4 . 3 2

2 . 6 8
d) 9.4 – 3.13

9 . 4 0

-3 . 1 3

6 . 2 7

e) 11.01 – 10.11

1 1 . 0 1
-1 0 . 1 1

0 . 9 0

f) 24.1 – 18.39

2 4 . 1 0
-1 8 . 3 9
5 . 7 1

g) 0.62 – 0.23

0 . 6 2
-0 . 2 3

0 . 3 9
 h) 8 – 6.04

8 . 0 0

-6 . 0 4

1 . 9 6

2. Subtract. Add to check your subtraction

a) 14.1 – 9.25
Add to check your answer

1 4 . 1 0

- 9 . 2 5

4 . 8 5

b) 4.37 –0.65

4 . 3 7

-0 . 6 5

3 . 7 2

c) 12.35 – 4

1 2 . 3 5

- 4 . 0 0

8 . 3 5

d) 15.1 – 12.05 (do as homework in notebook)

3) What should be added to 2.1 to get 10?

Solution: 2.1 + = 10
1 0 . 0
- 2 . 1
Number to be added = 10 – 2.1 = 7.9 7 . 9

So 7.9 should be added to 2.1 to get 10.

4) What should be taken away from 15 to get 3.96?

Solution: 15 - = 3.96
1 5 . 0 0
- 3 . 9 6
Number to be taken away = 15 – 3.96 = 11.04 1 1 . 0 4

So 11.04 should be taken away from 15 to get 3.96.

5) Omitted
6) Application in real life. Use addition or subtraction to solve.

a. Akshit’s father drove 158.3 km on Monday and 79.8 km on

Tuesday. How manykilometres less did he drive on Tuesday?

Solution:
Distance travelled on Monday = 158.3 km
1 5 8 . 3
Distance travelled on Tuesday = 79.8 km - 7 9 . 8
158.3 > 79.8 7 8 . 5

Difference = 158.3 km – 79.8 km = 78.5 km

Therefore, Akshit’s father drove 78.5 km less on Tuesday.

b. A bean plant measured 8.5 cm on Friday. It grew another 0.75 cm

on Saturday.What was its height on Saturday?

Solution:
Height on Friday = 8.5 cm 8 . 5 0
Growth on Saturday = 0.75 cm +0 . 7 5
9 . 2 5
Height on Saturday = 8.5 cm + 0.75 cm = 9.25 cm
Therefore the height of bean plant on Saturday was 9.25 cm.
 c. The thickness of one book is 3.8 cm. The thickness of another is
2.03 cm. What isthe thickness of the two books together when placed one
on top of the other?
Solution:
3 . 8 0
Thickness of one book = 3.8 cm +2 . 0 3
Thickness of another book = 2.03 cm 5 . 8 3

Total thickness = 3.8 cm + 2.03 cm = 5.83 cm

Therefore the thickness of the two books together when placed one on top of the other
is 5.83 cm.