i'll give an example. okay lets say you have a decimal of 0.9. The nine is in the 10ths place. So it would be 9/10. I'll give a harder one. so you have 0.25. What you will do is see that the last number, being 5, is in the 100ths place. So it will look like this 25/100. Then you will reduce it. So the way I find best is seeing what they both divide by that will make a whole number (without decimals) they both can be divided by 5. So 25/5=5 . 100/5= 20. It can still be reduced. So 5/5=1. 20/5=4
So the answer would be 1/4.
Hope that helps.