Page 76 - ICSE Math 2

T O
(e) There were 75 toff ees in
a packet. Shalini gave 48 toff ees

to her friends. How many toff ees –
are le in the packet?

Answer: toff ees are le in the packet.

T O

(f) How much less is 37 than 98?

–

Answer:

Mental Subtraction

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

Method 1

To subtract 2-digit numbers, break the number to be subtracted into tens and
ones. Subtract in parts.

Look at the given examples.

(a) 76 – 45 (b) 97 – 28

76 – 45 = 76 – 40 – 5 97 – 28 = (97 – 20) – 8

= (76 – 40) – 5 = 77 – 8 = 69

= 36 – 5 = 31

Method 2

Instead of subtrac ng, fi nd the number to be added to the smaller number to

get the bigger number.
Note: This method
Look at the given examples.
works if the two
(a) 91 – 88 (b) 59 – 53 numbers are close to
each other.
88 + 3 = 91 53 + 6 = 59

So, 91 – 88 = 3. So, 59 – 53 = 6.

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