In order for you to write a decimal into a fraction, you will be required to write down the decimal divided by 1 like decimal/1. Multiply both top and bottom by 10 for every number after the decimal point. For example, if there are two numbers after the decimal point, then use 100, and if there are three then use 1000. Read more on www.mathsisfun.com/converting-decimals-fractions.html.
Let's say you have 1/5. You have to get your denominator to a number like 10, 100, or 1,000. So 5 times 20= 100. now you do your numerator. Multiply it how you did with your denominator so 1 times 20= 20 so you have your fraction as 20/100. Then 20/100 coverts to 0.20
I like the 1st and 3rd answer....or you take the numerator and divide it by the denominator using long division. You'll have to put a decimal behind the whole number under the division bar and add a few zeros.