Question

Roberta is thinking about joining the food co-op store. If she pays $10.00 to join, she will get 10% off on all the groceries she buys there. How much must she buy before her savings equal her membership fee?

Answer 1

Hold on, let's read the question a bit more closely.
Roberta will save 10% on groceries, so if she buys $1 worth of food, she'd save 10% of that, which is only $0.10.
We want to find the amount Roberta would need to buy in order for her savings to be equal to the membership fee ($10)
We can represent this as an equation: 10%*(Money spent) = $10.00
To make this clearer, let's rewrite it as 0.1*m = 10, since 10% is also equal to 0.1 or 1 tenth.
Divide both sides by 0.1 to get m by itself, and you should be able to find the amount of money Roberta needs to spend