1. Barbara bought 4 dolls. Each doll cost $ 4. How many dollars did she spend on the dolls?   2. Michelle has 6 dolls. Each doll has a yellow dress, a red dress, and a green dress. How many dresses are there in all?   3. Robert has 4 toy cars. How many total wheels are there on the toy cars?   4. Robert arranges 9 blocks in a tall stack. He makes 9 such stacks. How many total blocks are there in the stacks?   5. Sarah multiplied 9 by 6 on her toy calculator. What product did the calculator display?