Question. GiGi took out a big bowl of mushrooms from the refrigerator. She cut each mushroom into 4 pieces. Her twins, Kenny and Karla sprinkled mushrooms on their pizzas and baked them in the oven. Kenny grabbed a handful and sprinkled 38 mushroom pieces on his pizza. Karla scooped them up with both hands and sprinkled 42 mushroom pieces on her pizza. On the cutting board, were 8 pieces of mushrooms remaining. How many mushrooms did GiGi cut up at the beginning?
Answer. 22
What step-by-step reasoning justifies that answer?
Reasoning: Kenny used 38 / 4 = 9.5 mushrooms on his pizza. Karla used 42 / 4 = 10.5 mushrooms on her pizza. Together, the twins used 9.5 + 10.5 = 20 mushrooms. There are 8 / 4 = 2 mushrooms left on the cutting board. GiGi cut up 20 + 2 = 22 mushrooms at the beginning.