1. Barbara bought 6 dolls for $ 6. She had $ 81 in her purse. How many dollars are left in her purse?   2. Michelle has two dolls. The first doll is 16 cm tall and the second is 10 cm. What is the difference in their heights (in cm)?   3. Brian had 55 marbles in his school bag. He returned home with 46 marbles. How many marbles did he lose?   4. Brian arranges 14 blocks in a tall stack. Accidentally, he drops 6 blocks. How many blocks are still there in the stack?   5. Each day 64 vans are made in a toy factory. Of these, 7 are defective. How many toy vehicles are not defective?