Help please math 10 starts?

PROJECT: 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

To multiply any number by 9, just add zero to the right of the number and subtract the number. For example, you need to multiply 123 by 9
123 x 9
= 1230 - 123
= 1107.