**Multiplication of a decimal Fraction by a Power of 10: Rule:** Shift the decimal point to the right by as many places of decimal as is the power of 10.

**Multiplication of Decimal fractions:- Rule :-** Multiply the given numbers considering them without the decimal point. Now, in the product, the decimal point is marked off to obtain as many places of decimal as is the sum of the number of decimal in the given numbers.

**Dividing a Decimal fraction By a Counting Number**

**Rule: –** Divide the given number without considering the decimal point by the given counting number. Now, in the quotient, put the decimal point to give as many places of decimal as are there in the dividend.

**Dividing a Decimal fraction By a Decimal Fraction**

**Rule: –** Multiply both the dividend and the divisor by a suitable power of 10 to make divisor a whole number. Now, proceed as above.

**H. C. F. & L. C. M. of Decimal fractions:- Rule :-** In given numbers, make the same number of decimal places by annexing zeros in some numbers, if necessary. Considering these numbers as without decimal point, find H. C. F. or, L.C.M., as the case may be. Now, in the result, make off as many decimal places as are there in each of the given numbers.