Fraction/Decimal Percent Conversions

To go from a fraction to a decimal, you DIVIDE the top by the bottom.

Think about the fraction bar as a division sign. (Top divided by bottom).

To solve  $\frac{4}{5}$   you would do 4 $\div$  5 which equals 0.8

You write it like you say it..

You would say 0.7 as "seven tenths" so you write it as $\frac{7}{10}$  

You would say 0.685 as "six hundred eighty five thousandths," so you would write it as  $\frac{685}{1000}$  .

You would then simplify to get  $\frac{137}{200}$  .

Notice that 0.685 has 3 digits after the decimal. 1000 also has 3 zeros. So, a hint is to be sure the number of digits AFTER the decimal is the same as the number of zeros in the denominator (before simplifying).

When you are converting to a percent, you move the decimal to the RIGHT two places. (You are also multiplying by 100).

For example: 0.65 becomes 65%.

When you are converting to a decimal from a percent, you move the decimal to the LEFT two places. (You are also dividing by 100).

For example, 70% becomes 0.70

IF YOU DO NOT SEE THE DECIMAL (in the percent), IT IS UNDERSTOOD TO BE TO THE RIGHT of the number.

For example: 70% has a decimal at the RIGHT 70.%

Also, 543% has a decimal at the RIGHT 543.%

To convert a fraction to a percent, FIRST convert the fraction to a decimal (top divided by bottom). THEN, convert that decimal to a percent by moving the decimal to the RIGHT two places.

For example  $\frac{9}{12}$   as a decimal would be 0.75.

0.75 as a percent is 75%

Percent means "part of 100".

This means that every percent get put OVER 100.

40% becomes $\frac{40}{100}$  

Then, simplify by dividing both top and bottom by 10 to get  $\frac{4}{10}$  .

Simplify even more by dividing both top and bottom by 2 to get  $\frac{2}{5}$  .