Question: Era had 5 burgers for her and her 4 friends. She sliced each burger into halves. The first and second friends got 1 and 2 slices, respectively. Then the third and fourth friends got 3 slices each. How many slices of burgers are left for Era? Think carefully first, then make a decision:
There are 5 x 1 / 2 = 10 halves of burgers made from 5 whole burgers. Era's first and second friends got 1 + 2 = 3 slices together. Her third and fourth friends got 3 + 3 = 6 slices together. Era's four friends got 3 + 6 = 9 slices. So, Era is left with 10 - 9 = 1 slice. So the answer is 1.