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%`
