Fractions what is the answer for 3/4 or 1/15 x 6 1/2?

My nephew just came over and his mom is peved that he is failing math anyways I have mostly no clue on how to do it either one of the problems said write each as an improper fraction. 2 3/4= he put 23/4 I thought it would be 6/1 or just 6 but I can't find a website with the answers. also another one was mulitiplying mixed numbers. Simplify if necessary. the question was 1 1/5 x 6 1/2 =. he put 6 1/10 = 6 1/5 it seems right ,but she put a x on the answer ,oh this is all of his last text he is in 5th grade. he made a 34 f on it with 15 questions. is their a website that can teach us how to do it the fun way becuase he gets borded and distracted very easy and it needs to be fun for it to sink in. I just gave him a work sheet off the computer and he made a 100% ,but I can't find one where you multiply mixed fractions.