Page 82 - Math Smart - 7

Check My
Understanding

Add.
a) 1 kg + 2.3 kg b) 34 g + 4.9 g c) 1g + 99.9g d) 4.53 g +1.22 9
e) 5.32 kg+ 1.71 kg f) 0.5 kg+ 0.05 kg g) 3.2g + 4.32g h) 3.7 kg + 0.21 kg

Work out the amount of change,
a) $5.30-$5.00 b) $2.67-$1.00 c) $12.00-$11.20 d) $21.00-$0.99
e) $4.53-$1.22 f) $5.20-$4.32 g) $2.99-$1.17 h) $0.89-$0.07
Work out each of the following.

a) 12.01+2.2 b) 9.09 + 1.1 c) 6.548 + 0.101 d) 4.21 +2.003 e) 4.99 + 0.01
f) 12.01-2.2 g) 3.452-2.132 h) 4.203-1.01 i) 0.5-0.05 j) 5.01-1.99
k) 16:5-6.7 I) 1.33 + 13.3 m) 6.52-0.2 n) 6.3 - 2.03 o) 5.099 + 0.001
p) 32.8-12.02 q) 43.62-41.8 r) 15.23 + 16.1 s) 0.5-0.05 t) 5.01 + 1.99
o Calculate.
a) 2.65 + 1.23 + 5.21 b) 2.05 + 0.33 + 7.2 c) 1.68 + 0.03 + 6.471
d) 0.05 + 1.99 + 0.201 e) 13.21 +0.943 + 0.708 f) 4.1 + 1.706 + 0.98

Fill in the missing digits in the blank spaces to make each statement true.
a) .3 + 1.2 = 7.5 b) 9.5 + .1 =9.6 c) 2.. .6 = 4.8
d) .4-1.1 =2.3 e) 9.4-_ _.3 = 7.1 f) 6.. .4 = 3.2

O* Challenge! Fill in the blanks to make each statement true,
a) 8.4- .5 = 7.9 b) 7. 5+15.1 = 2. .16 _.3+1 .2_ =12.58
Joe has added the decimals 6.01 and 7.3 incorrectly.
6.01
Correct his calculation and explain how he can add the decimals correctly.
+ 7.3
67.4

You have already learnt that decimals are often used in measurements.
Now let us look at more adding and subtracting decimals In everyday life.

Example 2

Mimi bought 2.38 kg of peanuts and 1.62 kg of raisins.
How many kilograms of snacks did she buy altogether?

+1 +1
Remember to line up the 2 . 38
decimal points. + 1 .62
4 . 0 0

Mimi bought 4 kilograms of snacks altogether.