This is a worksheet for use with ETA's VersaTiles, which are a great self-checking device. Even if you do not have VersaTiles you can still use the worksheet as a regular worksheet, there just won’t be a self-check. This worksheet consists of applying the concept of "Pirate Numbers" (thought by AoPS) in which symbols stand for different amounts. A • stands for one, an X for ten, and a C stands for one hundred. This product is for single-classroom/teacher use. Please remember to rate this product