Doodles Do Algebra – Lesson 33


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



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


Today your child begins the more formal part of algebra and to start with he will learn to evaluate equations. This is basically taking an algebraic equation and using given numerical values for the constants and unknowns (the a-b-c’s and x-y-z’s) to calculate a final answer. If you have a child who asks the dreaded, “But why do I need to know how to do this?” all you need to do is explain using his interests as a backdrop. For the boy who loves video games, you can explain that programmers use formulae like these to describe pictures and movements and even the effects of gravity on your favorite video game character. At any instant the program can calculate the position of an Angry Bird to display on the screen by taking set values like the ones DoodlePoodle provides at the start of the Doodle Dailies and then inserting them into an equation like any of the ones in today’s problems to calculate the position of the Angry Bird. If you don’t have Algebra and evaluating equations, you wouldn’t have Angry Birds.


  1. 12
  2. 14
  3. 13 (remember the order of operations (you do multiplication and division first, left to right, and then go back and do addition and subtraction, unless there are parentheses which you do first)
  4. 24-4/18-16=8-2/9=7 7/9
  5. 64/8-24=8-24= -16

(if the last two questions give your child some trouble, not to worry, just walk him through the process and make him feel good about understanding. He will practice and practice and practice this over the next months, so there is no point in forcing him to figure it out on his own and having him struggle. Confidence is everything here)