MULTIPLICATION OF DECIMALS -
We are very much aware of multiplication of digit, now we will learn about decimal number multiplication.
Example.1) 24.5 X 5.6 = ?
Ans.) 24.5 X 5.6
First we need to ignore the decimal places for both the given number to multiply, and multiply like general multiplication.
2 4 5 Multiplicand
X 5 6 Multiplier
------------------------------
1 4 6 0
1 2 2 5 X
-----------------------------------
1 3 7 1 0 Product
As we can observe that, in the both multiplicand and multiplier there are 1 decimal place, so total 2 decimal places. So now we have to move decimal point up to two decimal places from right to left of 13710, so the result is 137.10 (Ans.)
Example.2) Find 125.25 X 25.64
Ans.) 125.25 X 25.64
First we need to ignore the decimal places for both the given number to multiply, and multiply like general multiplication.
1 2 5 2 5 Multiplicand
X 2 5 6 4 Multiplier
-----------------------
5 0 1 0 0
7 5 1 5 0 X
6 2 6 2 5 X
2 5 0 5 0 X
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3 2 1 1 4 1 0 0 Product
Product of the two given number is 32114100. As we can observe that, in the both multiplicand and multiplier there are 2 decimal places, so total 4 decimal places. So now we have to move decimal point up to four decimal places from right to left of 32114100, so the result is 3211.4100 or 3211.41 (Ans.)
Example.3) Find 8.5 X 25.35
Ans.) 8.5 X 25.35
8 5 Multiplicand
X 2 5 3 5 Multiplier
-------------------
4 2 5
2 5 5 X
4 2 5 X
1 7 0 X
----------------------------
2 1 5 4 7 5 Product
So, the product of the given two numbers is 215475. As we can observe that, in multiplicand there is 1 decimal place and multiplier has 2 decimal places, so total 3 decimal places. So now we have to move decimal point up to three decimal places from right to left of 215475, so the result is 215.475 (Ans.)