This mental math game help students practice subtracting a 1-digit from a 2-digit number. Students can play the game several times because the exercises are never the same.

The picture in the game is gray and students can turn it into vivid colors by writing the correct answer. All the wrong answers must be corrected to remove the grayness.

Students can measure how much time they need to complete the task and they can see if their subtraction skills are improving.