1. Sarah bought 6 dolls for $ 6. She had $ 49 in her purse. How many dollars are left in her purse?   2. Stacy has two dolls. The first doll is 18 cm tall and the second is 12 cm. What is the difference in their heights (in cm)?   3. Paul had 54 marbles in his school bag. He returned home with 49 marbles. How many marbles did he lose?   4. Paul arranges 12 blocks in a tall stack. Accidentally, he drops 9 blocks. How many blocks are still there in the stack?   5. Each day 65 buses are made in a toy factory. Of these, 5 are defective. How many toy vehicles are not defective?