"Number Crossword Puzzles" feature a grid of squares like you would expect to see in a regular crossword puzzle, but instead of giving clues about words, each clue contains a review math problem, and students fill the answer into the puzzle instead.

Clues are organized like a traditional crossword puzzle, with clues numbered and separated by whether the answer is written across or down. Problems include grade-level appropriate tasks that range from mathematical operations to writing smaller numbers, identifying the digits in certain place values, completing number patterns, and more. Problems are chosen to encourage mental math, as there isn't a lot of extra space to work out each problem on the page.

In some cases, items include a double answer. For example, students might have to answer two problems to figure out which digits go in the boxes for 3 Down. Examples with answers are given at the top of each worksheet so students can see how it's done.

Reviewing math and encouraging mental math help students solidify important concepts. Incorporating puzzles into the review process can help keep them engaged and make reviewing for a test more exciting. In addition, puzzles can help teachers gauge which skills students are proficient at and which ones they could use a little more practice with.

For example, numbers could be filled into a crossword instead of letters, where math problems are provided in place of clues. Students could find their way through a maze by using greater than and less than directional arrows to compare numbers, or they could reveal a hidden picture by coloring in the squares according to the answers they get.