# Mathematics Principles V11

Clive W. Humphris

PERCENTAGES: Decimal to Percentage.

Percentages are useful to express relative quantities. For example a store person can ensure stock levels never fall below say, 80% of an agreed level is much better than trying to calculate the exact number for each type of product. Relative comparisons can be quickly made without have to resort to making lengthy calculations.

A percentage is a fractional part of a number based upon a hundred parts. Percentages greater than 100 are found by multiplying the whole number × 100 before adding to the percentage calculated for the fractional part. Calculators normally ignore whole numbers.

Input a decimal value of less than one, try 0.36 as an example.

The number line is used to graphically show percentages in relation to the whole. If you now include a whole number part by inputting say, 14.36 it will be seen that the two parts are dealt with quite separately. The whole number 14 is 1400% and the fractional part is 36%. The two are then added together to make the percentage conversion.