Addition/subtraction facts, 2nd grade: number rainbows and fact families

This video helps students practice subtraction facts where you subtract from 11, such as 11 - 2 and 11 - 7. For that, we use both fact families with 11, and a NUMBER RAINBOW. In the number rainbow, we connect two numbers with an arc if their sum is 11. This visual tool clearly shows students how the numbers are paired to make 11. We also briefly go through all the fact families with single-digit numbers where the sum is 11 (one with 1 + 10, another with 2 + 9, then one with 3 + 8, one with 4 + 7, and one more with 5 + 6). Lastly I drill the viewers with the subtraction facts -- Mathy joins in that also! I pause for a little while to let children answer the facts - thus this video can take the place of drilling by a teacher. Check out also Math Mammoth Grade 2 curriculum at