- Multiplication of decimals
To multiply a decimal by another decimal, first remove the decimal point and perform
the ordinary multiplication. In the result, place the decimal point as many places
from the right as the total number of decimal places in the numbers.
Initially, enable the child to understand that multiplication of decimals needs removal
of the decimal points as the first step. Once the decimal is removed, the process is
similar to ordinary multiplication. After multiplication is over, then the decimal point
must be placed in the final result based on the number of decimal places in the given
numbers. Use of abacus for calculation and writing down the numbers in Braille
would enable the child to understand the process better.
Eg : Multiply : 15.21^ × 14.12
Therefore 15.21^ × 14.12 = 214.7652
- Division of decimals
To divide a decimal by another decimal, first convert the denominator (the divisor) into
a whole number by multiplying by 10, 100 or 1000 etc., whichever is suitable. Then
multiply the numerator (the dividend) also by the same number and then divide it.
Make the divisor a whole number by multiplying it by suitable power of 10 and then
divide.
Eg. : Divide :^80 ..^2648002
0.002 has 3 decimal places. So multiply it by 1000 to make it a whole number. When
the denominator is multiplied by a number the numerator should also be multiplied
by the same number.