Lesson 118 – Doodles Do Algebra

lesson118doodlegirlToday your child gets to do some word problems using what he learned about solving simple equations in the last several lessons. These are the same types of problems that he did when he began this Doodles Do Algebra series in the “mental math” section of the curriculum.

If you tell your child that he has already done problems like this – and done them in his head – he will have the confidence to overcome any initial uncertainty.

We walk your child through the solving process with boxes to fill in as a way to get him started setting up the problems.

Download Lesson 118 of Doodles Do Algebra HERE

Answers:

1. x=first number and 2x (or twice the first) = second number. Then x+2x (or their sum) = 33. Now we just solve.

x+2x=33 first add the terms on the left since they both have the variable, x, in them

3x=33 now divide both sides by 3

x=11 and you have your answer: the first number is 11 and the second number is 22.

2. x=Daddy’s age and 2x (twice as old) = Grandpa’s age. Then 2x-x (or the difference between their ages) = 25. Now we solve for x.

2x-x=25 first combine the terms on the left since they both have the variable, x, in them

x=25 no dividing by the coefficient in this problem since the coefficient happens to be 1

Now you have your answer by looking at the original definitions: Daddy is 25 and Grandpa is 50.