Use the eraser tool to scratch off any box from the six boxes within the green rectangle. You will reveal a hidden number to use as the total in your number sentence. Then, use the eraser tool again to scratch off any box from the nine boxes within the purple rectangle. You will reveal another hidden number for you to use as the known part in your number sentence. Use the numbers you found to write a subtraction sentence below in the blue rectangle. Remember to find the missing part and write it in your subtraction sentence.
The totals in this activity range from 10 to 20. Thanks Kris Szajner for the scratch off idea!