Page 35 - Start Up Mathematics_4

Example 6: Add 6,34,925; 1,47,156; 79,685 and 1,03,219.

Solution: L TTh Th H T O
1 6 2 3 1 4 1 9 2 2 5

1 4 7 1 5 6

7 9 6 8 5

+ 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.

Finding the Missing Digits

We can find the missing digits in an addition sum by following the given formula:
Sum – one addend = the other addend

Example 7: Find the missing digits.
TTh Th H T O

1 ? 3 ? 4

+ ? 6 2 5 ?

6 8 ? 4 1

Solution: Step 1: Look at the ones column.

4 + ? = 1 TTh Th H T O
1 is smaller than 4. 1 ? 3 1 ? 4

So, we find a number which when added + ? 6 2 5 7
to 4 gives a sum whose unit digit is 1.
6 8 ? 4 1
4 + 7 = 11
11 is a 2-digit number. Keep the 1 one and carry over the 1 ten.

So, we write 7 in the blank space. TTh Th H T O
Step 2: Look at the tens column. 1 1
1 ? 3 8 4
1 + ? + 5 = 4
+ ? 6 2 5 7

6 + ? = 4 6 8 ? 4 1
4 is smaller than 6.
So, we find a number which when added to 6 gives a sum whose unit
digit is 4.

6 + 8 = 14

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