"Today I will teach you a trick that will make multiplying by 9's easier!"
Teacher introduces topic.
Count how many fingers are up on the right side of the finger that is down, now count how many fingers are up on the left side of the finger that is down. Put those two numbers together, and you have your answer.
Teacher holds hands up. Count each finger 1-10.
Think of a number you want to multiple by 9.
Put the finger number that you are multiplying 9 with down .
Repeat the previous steps with a different number and example.