1. Barbara bought 7 dolls for $ 7. She had $ 88 in her purse. How many dollars are left in her purse?   2. Debbie has two dolls. The first doll is 24 cm tall and the second is 18 cm. What is the difference in their heights (in cm)?   3. Arthur had 31 marbles in his school bag. He returned home with 23 marbles. How many marbles did he lose?   4. Arthur arranges 11 blocks in a tall stack. Accidentally, he drops 4 blocks. How many blocks are still there in the stack?   5. Each day 47 cabs are made in a toy factory. Of these, 8 are defective. How many toy vehicles are not defective?