Add. beth needs 1 2/3 cups of sugar to make a cake and 2 1/4 cups to make a pie. how much sugar does she need to make both?

It would be 3 11/12
set aside and add the 1 and 2. which gives you the 3. Then find the common denominator for 3 and 4. which is 12. whatever you do to the bottom you have to do to the top. so 3×4 and 2×4 so it's 8/12. 4×3 and 1×3 so it's 3/12.