Work with Denominator Danny

Danny adds (or subtracts) the tops and the bottoms separately, because they were both on the bottom.

Quick lesson

A denominator names the size of the pieces; a numerator counts them. You can only add or subtract counts of the same-size piece.
Rewrite each fraction over a common denominator (the least common multiple works best), scaling top and bottom by the same number.
Then add or subtract the numerators and keep the common denominator. Simplify if you can.

5 challenges. Spot the trick, understand it, fix the work, check the answer. Get 4 of 5 clean (first try or one retry per step) to tame Danny.

Prototype · results saved on this device only