CREATING AN ALGORITHM
Imagine working with a younger sibling or student who is having trouble multiplying by 9s. Create an algorithm to help the student learn how to do this easily. Then notate whether the given algorithm is equivalent or not. You may need to use outside resources to help you.

Hint: 10 - 1 = 9

Help please (:

Question

CREATING AN ALGORITHM
Imagine working with a younger sibling or student who is having trouble multiplying by 9s. Create an algorithm to help the student learn how to do this easily. Then notate whether the given algorithm is equivalent or not. You may need to use outside resources to help you.

Hint: 10 - 1 = 9


Help please (:

anonymous · Answer

Every number multiplied by 9 is the number multiplied by 10 - itself, that is:$$9n = 10n - n$$9*4 = 10*4 - 4 = 36 and so on.

unklerhaukus · Answer

count on you fingers
|dw:1335240908845:dw|
bend down the finger that is being multiplied by 9
fingers to left are worth 10 finger to the right are worth 1