Page 30 - ICSE Math 5

TTh Th H T O Top Tip
1 1 1 Avoid this common mistake while adding.
4 2 6 1 8
1 1 1 1
+ 3 7 9 5 6 8 2 6 4 5
+ 7 9 8 6
8 0 5 7 4
1 8 0 6 3 1 ()

So, 42,618 + 37,956 = 80,574. Add the carry over and do not combine it
It is written as eighty thousand with the digit to form a 2-digit number.
five hundred seventy-four

Example 3: Find the sum of 6,34,925; 1,47,156;
79,685 and 1,03,219. Mental Maths
Fill in the blanks.
Solution: L TTh Th H T O
(a) The sum of place values of two 5s in
1 2 1 1 2 8,59,256 is _______.
6 3 4 9 2 5
(b) 64,799 + 11 = _______
1 4 7 1 5 6 (c) 1 more than 7,00,009 = _______
7 9 6 8 5 (d) 54,567 + 12,635 = 12,635 + _______

+ 1 0 3 2 1 9

9 6 4 9 8 5

So, 6,34,925 + 1,47,156 + 79,685 + 1,03,219 = 9,64,985. It is written as nine lakh
sixty-four thousand nine hundred eighty-five.

Finding the Missing Digits

We can find the missing digits in an addition sum by considering the place values of the digits.
Let’s learn to find the missing digits with the help of an example.

Example 4: Find the missing digits.

TL L TTh Th H T O
3 ? 8 ? 7 ? 5

+ ? 1 ? 4 9 6 ?

5 9 4 1 ? 8 3

Solution: Step 1: Look at the ones column.

3 is smaller than 5 (3 < 5).
So, we find the smallest number which when added to 5 gives a sum which
has 3 in the ones place.
13 is the smallest number with 3 in the ones place.

Thus, 5 + ? = 13

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