Doodles Do Algebra – Lesson 5


Update: This Lesson Is Part of Book 1 of Doodles Do Algebra: “Starting Out With Mental Algebra” available on Amazon.


Teacher’s Notes:

Today’s lesson summarizes and reviews the ideas learned in the last 4 lessons. You have now met all the players in our math book. Each week, or five days, your child will get a lesson from each of our characters.



Available in the book, “Starting Out With Mental Algebra, Book 1 of Doodles Do Algebra”



  1. The crow breaks the 30 foot pole in two equal parts (half) so each part is one half of the total, or one half of 30 feet. Answer: each piece is 15 feet long.
  2. Your basement has a total of 20 barrels of root beer, the number of full barrels are four times greater than the number of empty barrels, so the total number of barrels is divided 5 “ways” – 4 for the full barrels and 1 for the empty. And that means that the number of barrels in each “way” is 20 (total number) divided by 5 (the number of “ways”), or 4. So there are 4 empty barrels and 4 times 4, or 16 full barrels.
  3. Here the farmer spends a total of $60. He buys a sheep, a cow, and a moose (this must be Canada or Montana). The cow is worth 3 sheep, and the moose is worth 2 cows, or 2 times 3 which equals 6 sheep. So the total money spent in sheep is 1 (for the sheep) plus 3 (for the cow) plus 6 (for the moose) which equals 10. So a sheep costs $60 divided by 10, or $6. The the final answer is Sheep: $6, Cow: $18, and Moose: $36.
  4. The two overly optimistic men on pogo sticks are hopping towards each other at the same speed. This means that they will meet in the middle. Since they start a whopping 48 miles apart, they will each travel 24 miles before they meet. If it takes them 6 hours to meet (in the middle), then each one travels 24 miles in 6 hours, or 24 divided by 6 miles per hour, which equates to 4 miles per hour, unrealistic at best but fun nonetheless.

By now, your child should be getting the basic hang of doing these types of problems in his or her head. The more fun you keep things, the easier it will go. And they will see it all again later, so just explain the problems that he or she gets stuck on and move along.