How do you write 0.09 as a fraction?

2 Answers
Nov 1, 2015

#9/100#

Explanation:

Every place value after the decimal point can be expressed as a fraction with #10# to some power in the denominator.

The first place after the decimal point is called the "tenths place" If I had #0.9#, I would have #9# tenths, or as a fraction #9/10#.

The second place after the decimal is called the "hundredths place". The question above asks for #0.09#. This would be #9# hundredths, or as a fraction #9/100#.

#0.09 = 9/100#

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#