My First Crossnumber Puzzle!

For the Upward Bound math class I'm teaching this summer, I've been trying to get the students to create their own crossnumber puzzles. Crossnumber puzzles are like crossword puzzles, but the answers are all numbers, and the clues can contain some math. Nobody took up my challenge, so I decided to create some myself. The crossnumber below is my first attempt, where I filled in a printed an empty US style crossword grid, but only used the top half in what you see below, which the Amuse Labs folks reformulated into a pretty lame (lots of black space) answer grid. For my next attempt, I'll either call them up to give me help in outputing the puzzle I want, or I'll just go ahead and do the whole puzzle.

Let me know what you think of the puzzle, and thanks for giving it a go!!