Using approximation to find the greatest fraction is something that will require you to figure out which is the bigger approximation. Use approximation to find the greatest fraction with help from a high school math tutor in this free video clip.

Hi, I'm Charlie Kasov, and this is how to use approximation to find the greatest fraction. Now to use approximation, let's pick up two examples. We have 5 over 29 and we have 7 over 34. So to figure out which one is bigger using approximation, we're going to figure out our reference points. Now 5 over 29 that's kind of close to 5 over 30, it's a little bigger than 5 over 30 but 5 over 30 is like 1 over 6 and 1 over 6 is .16. This is a worthwhile reference point to remember, 7 over 34 is a little bigger than 7 over 35 which is like 1/5th which is .2. So if we have a little bigger than .2, that's definitely going to be bigger than a little bigger than .16. So that's how you use approximation to find the greatest fraction.