Quest of Nine

The Book

Decimal fractions

Any fraction can be written in decimal form.

Some are easy to remember:

1/10 = 0.1      1/2 = 0.5
1/4 = 0.25      1/5 = 0.2

but you can work out any decimal fraction by dividing the numerator by the denominator.

e.g.
1/8 = 1.000 ÷ 8 = 0.125
3/4 = 3.00 ÷ 4 = 0.75

Can you work out the decimal fractions for some other fractions?

What is special about 1/3 and 1/6 ?

Are there any other decimal fractions like this?

Percentages

A percentage is a fraction represented at a part of 100.

Some are easy to remember:

e.g.
1/100 = 1%   20/100= 20%
1/2 =50%   1/4 = 25%

You can work out any percentage by multiplying a decimal fraction by 100

e.g.
1/10= 0.1 = 10%
1/8 = 0.125 = 12.5%
3/4 = 0.75 = 75%

You can use the calculator to find a percentage of a number.
e.g. What is 25% (1/4) of 64?

6 4 x 2 5 %