Percentage to decimals

Converting percentage to decimals you must remember

$100%=1$

This will then help you remember that:

$50%=0.5$

$25%=0.25$

$75%=0.75$

$33\1/3%=0.3dot3$

$66\2/3%=0.6dot6$

$10%=0.1$

$20%=0.2$

But knowing $100%=1$ will also help you solve any inbetween percentages.

Example 1

Express $0.31$ as a percentage

to do this remember $100%=1$

and also read this in conjunction with the section on percentages.

Which states

Write out what $100%$ is
Write out what we know
Keep $%$ on one side
Put the divide sign in

1. Write out what $100%$ is $100%=1$

2. Write out what we know $x%=0.31$

3. Put the divide sign in

$(100%)/(x%)=1/0.31$

Now work out what $x$ is

Multiply by $x$ on both sides to get $x$ on its own.

$(cancelx100)/cancelx=1/0.31timesx$

$100=x/0.31$

Multiply both sides by $0.31$ to get $x$ on its own.

$0.31times100=(xcancel0.31)/cancel0.31$

$x=100times0.31$

$x=31%$

Example 2

Convert $0.125$ to a $%$

1. Write out what $100%$ is $100%=1$

2. Write out what we know $x%=0.125$

(Keep the $%$ sign on the same side)

3. Put the divide sign in

$(100%)/(x%)=1/0.125$

Now work out what $x$ is

Multiply by $x$ on both sides to get $x$ on its own.

$(cancelx100)/cancelx=1/0.125timesx$

$100=x/0.125$

Multiply both sides by $0.125$ to get $x$ on its own.

$0.125times100=(xcancel0.125)/cancel0.125$

$x=100times0.125$

$x=12.5%$

Example 3

What is $1.04$ converted to a $%$

1. Write out what $100%$ is $100%=1$

2. Write out what we know $x%=1.04$

(Keep the $%$ sign on the same side)

3. Put the divide sign in

$(100%)/(x%)=1/1.04$

Now work out what $x$ is

Multiply by $x$ on both sides to get $x$ on its own.

$(cancelx100)/cancelx=1/1.04timesx$

$100=x/1.04$

Multiply both sides by $1.04$ to get $x$ on its own.

$1.04times100=(xcancel1.04)/cancel1.04$

$x=100times1.04$

$x=104%$

Example 4

What is $0.005$ converted to a $%$

1. Write out what $100%$ is $100%=1$

2. Write out what we know $x%=0.005$

(Keep the $%$ sign on the same side)

3. Put the divide sign in

$(100%)/(x%)=1/0.005$

Now work out what $x$ is

Multiply by $x$ on both sides to get $x$ on its own.

$(cancelx100)/cancelx=1/0.005timesx$

$100=x/0.005$

Multiply both sides by $0.005$ to get $x$ on its own.

$0.005times100=(xcancel0.005)/cancel0.005$

$x=100times0.005$

$x=0.5%$