1. Sarah bought 2 dolls for $ 2. She had $ 78 in her purse. How many dollars are left in her purse?   2. Michelle has two dolls. The first doll is 51 cm tall and the second is 45 cm. What is the difference in their heights (in cm)?   3. Robert had 68 marbles in his school bag. He returned home with 60 marbles. How many marbles did he lose?   4. Robert arranges 17 blocks in a tall stack. Accidentally, he drops 8 blocks. How many blocks are still there in the stack?   5. Each day 42 cabs are made in a toy factory. Of these, 3 are defective. How many toy vehicles are not defective?