Lesson 139 of Doodles Do Algebra

lesson-139Today’s lesson teaches your child to change rational quantities to radicals that have the same value. This is actually manipulating quantities in the reverse direction of the last couple of lessons, so once he realizes that, your child should have no problem with the lesson. The explanation and example on the worksheet for today explains the process very well so I won’t repeat it here.

This is one of those examples in algebra, and even more broadly in math, when there is no need to worry about review because topics a built one upon another. You child will learn a math skill and then use it again for more complicated math later. This is one of the reasons that I focused everything in our homeschool on getting my own kids through algebra. Then after algebra, they were equipped to understand not only geometry and trig and calculus, but also applications of algebra like economics and physics and chemistry and biology and marketing and accounting and even drafting dress patterns and pretty much everything.

So the ‘take-home’ message here is that the key to understanding the world lies in a solid understanding of math (at least through algebra and actually through calculus). And the reason we homeschool our children is to give them the best shot at understanding their world, in spite of the sacrifices that come out of that choice. But for us, the sacrifices are not really sacrifices at all. They are blessings and a general manifiestation of our duty as parents to do the best for our children. And algebra is key to it all.

So if you have questions about teaching algebra to your children, or if you just want to add your two cents, please comment below and I will respond.

Worksheet: Download Lesson 139 of Doodles Do Algebra HERE


1. Square root of 36

2. Cube root of 8

3. This is really a two step problem. First to express 3 as a square root (3 is the square root of 9), and second to combine the square root of 9 and the square root of 6. If your child has trouble here, remind him of the lesson a few weeks ago when he learned how to do this: multiplying the square root of one number (or quantity) by the square root of another is the same as the square root of the product of the two quantities. That means the answer is the square root of 9 times 6, or the square root of 54.

I apologize for having to write out these answers in English instead of using math symbols. I am having trouble finding a wordpress plug in that lets me display symbols like square roots, so bear with me for now.