# Lesson 111 – Doodles Do Algebra

Today your child learns how to resolve a fraction into a series and that sometimes you use this technique to approximate numerical answers to complex and perhaps unsolvable questions in physics, biology, medicine, or even architecture.

DoodleTwo takes your child step by step through the conversion of $1/(1-x)$ to $1+x+x^2+x^3+...$. and then asks your child to try to show that $1/(1+x)=1-x+x^2-x^3+...$. This is really quite simple – it is just a matter of copying the format of the example that is worked out on the worksheet and changing the ’1+x’ term to a ’1-x’ as you go. If you have trouble, just ask in the comments below and I will be happy to help.