How do you turn a decimal in to a fraction

It depends on how many decimal places there are.

If it has one decimal place, like 0.2, it's called 'two tenths' or 2/10.

If it has two decimal places, like 0.34, it's called 'thirty-four hundredths' or 34/100.

If it has three decimal places, like 0.842, it's called 'eight hundred forty-two thousandths' or 842/1000.

And so on ...

Afterwards you can simplify the fraction by finding the greatest common factor (GCF) of the numerator and denominator, then dividing the numerator and denominator by that number.