Page:Happy-Maths-1-English.pdf/18

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Try this

Let’s try 24 multiplied by 6. Let’s say you have 20 red marbles and 4 green marbles. Suppose you and five of your friends (that’s 6 of you) want to have the same number and kind of marbles each. When you want 6 times the number of marbles, you will have 6 times the number of red marbles in addition to 6 times the number of green marbles, right?

20 X 6 = 120

4 X 6 = 24

120 + 24 = 144 marbles. Easy!

Now try this. Multiply 34768 by 987 by the same method. You would have to write 30000 + 4000 + 700 + 60 + 8. Then multiply each of these by 7, 80 and 900. And add up all the answers to get your final answer. Doing this horizontally, then writing it down vertically and then adding the numbers is a very tiring process. To make this work simple, we follow a pattern of writing while multiplying big numbers.

34768 x 987
3 4 7 6 8 x 9 8 7
A. 2 4 3 3 7 6
B. 2 7 8 1 4 4 x
C. 3 1 2 9 1 2 x x
D. 3 4 3 1 6 0 1 6

A. Multiply 34768 by 7.
B. Put an X or a 0 in the unit’s place. Then multiply 34768 by 8.
C. Put X marks in the unit’s and ten’s place. Multiply 34768 by 9.
D. Add the answers you got in steps A, B and C.

It becomes easy to add the numbers vertically, starting from the right, if you write the digits neatly one below the other!