Do you need a quick and fun math warm-up? In search of morning work? Do your students need practice building number sense, mental math, and critical thinking? Give these math crossword puzzles a try. There are 31 puzzles with an answer key provided. They incorporate the 4 basic operations (addition, subtraction, multiplication, division). Students can work on these independently or in small groups. These puzzles can foster good number talks about strategies students used to figure them out. Hap