Drew gave 12 marbles to Marcus. Each boy then had 25 marbles. How many more marbles did Drew have than Marcus at first?

There are four pieces of paper in a bag. Each paper has a number on it. The numbers are 19, 23, 34, and 38. Harry took out one piece of paper. The sum of the remaining numbers was 76. What number did Harry remove from the bag?

A comic book costs 37 cents. The store owner reversed the digits by mistake. He wrote that number on the comic book. How much did the store owner overcharge his customer?

Mr. Bradley gave his class a math problem to solve. He said, "Begin with the number 28. Add 12 to it. Then add 7 more." Ned followed the instructions perfectly but Billy subtracted 7. What is the difference between the boys' answers?

Caitlin is on the 13th step of a giant slide. She walked down 4 steps to talk to her friend Dana. Then she walked up 12 steps to the top. How many steps does the giant slide have?