This video helps students practice subtraction facts where you subtract from 12, such as 12 − 3 and 12 − 7. For that, we use both fact families with 12, and a NUMBER RAINBOW.
In the number rainbow, we connect two numbers with an arc if their sum is 12. This visual tool clearly shows students how the numbers are paired to make 12.
We also briefly go through all the fact families with single-digit numbers where the sum is 12 (one with 2 + 10, another with 3 + 9, then one with 4 + 8, one with 5 + 7, and one more with 6 + 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.
If you cannot see the video above, click here for an alternative video player.
Fact families — free online practice
Number rainbow & fact families with 11
Number rainbow & fact families with 13
Number rainbow & fact families with 14
Math Mammoth Grade 2 curriculum