1. Debbie bought 3 dolls for $ 3. She had $ 12 in her purse. How many dollars are left in her purse?   2. Barbara has two dolls. The first doll is 81 cm tall and the second is 78 cm. What is the difference in their heights (in cm)?   3. Ronnie had 22 marbles in his school bag. He returned home with 18 marbles. How many marbles did he lose?   4. Ronnie arranges 15 blocks in a tall stack. Accidentally, he drops 9 blocks. How many blocks are still there in the stack?   5. Each day 45 cars are made in a toy factory. Of these, 9 are defective. How many toy vehicles are not defective?