Missing Subtraction

This app is designed to improve your problem solving skill. You are not doing the problem in the traditional way such as "what is 15 minus 5?". Here we turn the it all the way around. For example: "? - 5 = 10" means "what number minus 5 equal 10?" OR "8 - ? = 5" means "8 minus what number equal 5". This new approach will increase your flexibility when solving a problem with different given information.

*** TEACHER & PARENT: This is absolutely a useful tool to test your students/ children to see how they are doing. Only 3 to 5 minutes per day, you will see the improvement within a week.

*** NOTE: Read the question carefully and choose the correct answer from the list. Press the Hint button for the difficult questions.