Math Mights Add & Subtract using 10 Season 2 Episode 203 | 15m 59s | CC Represent 10 using a number bond and 10-frame with a missing addend. Use Notice and Wonder with a 10-frame, connecting cubes ...

The subtraction uses a complement addition similar to how you do binary subtraction using 2’s complement math. Multiplication is just repetitive addition, which is fine for simple problems.

Count back & use the relationship between addition and subtraction to subtract within 20.