Jim is running on a trail that is 5/4 of a mile long. So far he has run 2/3 of the trail. How many miles has he run so far?

You have to subtract 5/4 by 2/3 but in order to do that you must find a common denominator or least common multiple so the least common denominator of 4 and 3 is 12 so you have to multiply 4 by 3 and three by 4 to make both denominators 12 but you have to do the same thing on the top as you did the bottom so: 5/4*3 = 15/12 and 2/3*4=8/12 Then 15/12-8/12 is 7/12 so Jim has to run 7/12 more