Lesson 47 – Doodles do Algebra


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 starts multiplication (the algebraic kind). And just as we did with addition and subtraction, we begin with word problems. Those just make more sense to most people who were not taught in school to be afraid of them by teachers who could not understand or explain. I have found that kids generally have no problem at all with word problems, it really is just those of us who suffered through 7th grade algebra with surly middle school teachers who have a problem with word problems.

Once again, today’s lesson has a get-out-of-math-quick card for the child who reads the explanation and doesn’t just skip to doing the problems. The child who reads the top part of the page learns that all he has to do is the last problem on the sheet. The child who hates reading instructions finds herself going through the entire page until her twin brother walks by and asks why she is going to all that trouble. This is just another way I try to get my own kids to follow through and read instructions – every so often there is something really important in them.


1. 5 lemons cost 5 times as much as one lemon, so if one lemon is “a” cents, then 5 lemons are 5a cents.

2. 6 oranges cost 6a cents (same reasoning as in 1. above)

3. The cloth is c dollars per yard and the merchant bought b yards of it, so that is “bc” dollars for each piece. But the merchant bought “a” pieces so that is a total of “abc” dollars. If your child has trouble with this just substitute numbers for the a,b, and c variables first – solve the problem that way and then go back and show her how it would be just the same if you used and a or a b or a c to represent the numbers.