Page 118 - Start Up Mathematics_1

(d) 12 + 53 = (e) 84 + 11 = (f) 72 + 26 =

Tens Ones Tens Ones Tens Ones

+ + +

5 Add mentally and write True or False.

(a) 10 + 15 = 25 True (b) 16 + 20 = 46

(c) 22 + 13 = 34 (d) 43 + 30 = 73

(e) 51 + 33 = 84 (f) 62 + 24 = 87

Addition on a Number Line

We have already learnt that addition on a number line means counting forward.
Let’s learn how to add some more numbers on a number line.

Look at the example, 18 + 7 = ?

Starting from 18, add 7 by counting forward and you will reach 25.

So, 18 + 7 = 25.

17 18 19 20 21 22 23 24 25 26

Alternate Method

Step 1: Draw a line and write start at the left end.

start

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