Page 61 - ICSE Math 2

11. Frame two word problems each for the addi on of the given numbers.

(a) 63 + 6 (b) 45 + 22 (c) 13 + 76

(d) 38 + 42 (e) 36 + 12 (f) 10 + 29

Mental Addition

To perform mental addi on, we can use some addi on shortcuts as discussed
here.

Method 1

To add 2-digit numbers, break the number to be added into tens and ones. Add

the tens and ones separately.

Look at the given examples.

(a) 36 + 20 (b) 13 + 27

36 + 20 = 30 + 6 + 20 13 + 27 = 10 + 3 + 20 + 7

= (30 + 20) + 6 = (10 + 20) + (3 + 7)

= 50 + 6 = 56 = 30 + 10 = 40

Method 2

Add an easy number close to the actual number and then correct the answer.

Look at the given examples.

(a) 23 + 47

47 is close to 50. (47 + 3 = 50)

So, add 50 to 23.

23 + 50 = 73

Now, correct the answer by subtrac ng 3 from 73, as we added 3 more
than 47.

So, 73 – 3 = 70.

(b) 6 + 86

90 is close to 86. (86 + 4 = 90)

So, add 90 to 6.

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