This is one of my favorite tools to use for place value. Each student is provided with his/her own place value cheat sheet. I printed out enough for each student on cardstock, then laminated each one. Although it was a little extra work in the beginning, my students used this tool consistently throughout the year.
When laminated, this product provides a dry-erase tool for students to use when working with large numbers. Each student had this attached to the top of his/her desk after we initially introduced place value.
On the cheat sheet, the students are provided with the millions, thousands, and units broken down into even smaller categories. The hundreds are depicted with a "big, bad bully" because the "bully always makes you say his name." The tens and ones are depicted with "best friends" because you read them together. For example, 121 is read as "One HUNDRED, twenty-one." To the right-hand side, students are also provided with the spelling for the numbers 1-20 and 30, 40, 50, 60, 70, 80, 90.