This interactive mental math worksheet is prepared for practice subtraction up to 20 with regrouping.
Kids need a lot of training to become fluent in solving subtraction questions. The motivation for learning with this worksheet is higher because there is a gaming element - color the tractor.
Every correct answer will color the part of the tractor. Kids can try to solve the subtraction problems several times if their answers are wrong.
The worksheet also has a timer, so teachers and students can measure the time they need to solve all the subtraction questions.