Decimals consist of a whole number and a decimal fraction.
Decimal = Whole number + Decimal fraction
7.8 = 7 + 0.8
Decimal fractions are numbers written after decimal points; example, .8 is a decimal fraction. The numbers after the decimal point are actually the numerators of a fraction, with the denominator having as much zeros as there are numbers in the numerator. For example, the decimal fraction .8, is as a fraction; 0.73, is .
The procedure for multiplying decimals is the same as multiplying whole numbers. On completing the multiplication, the next step is to determine where the decimal point should be placed; count the amount of numbers behind the decimal point in the numbers multiplied, that amount, is the number of places that should be behind the decimal point in the product.
Before dividing, do the following: (1) Turn the divisor (the number that is doing the dividing) into a whole number by moving the decimal point to the right of the last number. (2) Move the decimal point of the number being divided to the right, by the same amount of places as the divisor was moved. On completing, carry out the division placing the decimal point in the quotient, at the exact point where it is in the number being divided.