Joe spent 1/3 of his allowance on a model airplane. He spent 2/3 of the remainder on a fishing rod. He had $20 left over. How much did he start off with?

>> I'm starting my son off with a picture that is a rectangle divided into 3 parts (thirds), the first part representing the model airplane, but then I'm confusing myself with representing the 2/3 of the remaining 2 parts to arrive at the total. I know the answer is 90, but I can't explain how I got there except in the most manual, illogical way. I need a better mental template to approach these word problems with. Can I see a good step-by-step solution?

Thank you!

morgaine300

No harder than explaining your equation to a child?? And Unky just did quite a nice picture, a bit like I had in mind. Except it doesn't actually need to be divided into 9 parts to solve it. Trust me, it doesn't. Give me a 6th grader and I'll prove it to you.

Nhatkiem

Who said that formulaic explanation was for the child? The guy asked it merely for himself.

As requested by OP "I need a better mental template to approach these word problems with. Can I see a good step-by-step solution?"

morgaine300

Well, that's true... but I still see no issue with my suggestion.