Practice addition and subtraction with numbers that have sums or differences within 20
Students review and strengthen their understanding of basic addition and subtraction facts. They work with single-digit numbers and teens, building fluency with mental math strategies. This foundational skill supports their multiplication work by reinforcing number relationships and computational thinking.
Move the sliders to change the two parts. Watch the whole and the equation update.
Start with the whole, take one part away, and see what is left.