How do you write 0.09 as a fraction?

2 Answers
Nov 1, 2015

9/1009100

Explanation:

Every place value after the decimal point can be expressed as a fraction with 1010 to some power in the denominator.

The first place after the decimal point is called the "tenths place" If I had 0.90.9, I would have 99 tenths, or as a fraction 9/10910.

The second place after the decimal is called the "hundredths place". The question above asks for 0.090.09. This would be 99 hundredths, or as a fraction 9/1009100.

0.09 = 9/1000.09=9100

Explanation:

I enjoy working with decimals because every one converts to a fraction that has a denominator of 10 or a power of 10.
Powers of 10 simply means adding more zeros.
10, 100, 1000 ...

After working with a few of these examples you will see a trend.
Every time you have another decimal place in a decimal number, then you will need that many zeros in the denominator to create a fraction from the given number.

So 0.09 will give us a whole number of 9 for the numerator and there are two decimal places. That indicates there will be two zeros in the denominator to give 1/100.

0.09 = 9/100

Try also converting 0.1085 to a fraction.
Numerator is 1085 and there are four decimal places.
Denominator now needs four zeros to give 1/10000

0.1085 = 1085/10000 which simplifies to 217/2000

What about decimal numbers greater than 1?

Convert 25.492 to a fraction.

The whole number is already 25, the decimal part needs to be written as a fraction

Numerator is 492 and there are three decimal places.
Denominator now needs three zeros to give 1/1000

25.492 = 25 492/1000 which simplifies to 25 123/250

Note that this can also be written as 25492/1000 = 6373/250