# Doodles Do Algebra – Lesson 41

Update: This Lesson Is Part of Book 3 of Doodles Do Algebra: “The Basic Math of Algebra” available on Amazon.

Worksheet:

Available in the book, “The Basic Math of Algebra, Book 3 of Doodles Do Algebra“

This week we start subtraction in algebra. And today we start by going back to the type of mental math (word problems you do in your head) that we began this course with. The idea today is for your child to understand that “gives away” and “take away” means to subtract. This should be old news for him at this point but we are adding the concepts of unknowns (that he learned about more recently) to the mix.

Problem 1. $3a Cents$
Problem 2. $8axy$
Problem 3. $a^2$