Missing Numbers: Addition and Subtraction Sentences up to 20

Find missing numbers in addition and subtraction sentences. This mental math game has three sets of 16 math problems.

There are also hidden pictures and puzzles that make learning fun, and students' motivation for calculating last longer.

Feedback information is available. Teachers can see the statistics about the solved task. (correct answer, wrong answer, time).

This mental math game students can play at home or in the classroom.