Predict: I predict this will be about addition.
Read: Which deal costs less per gram.
clarify: I had nothing to clarify.
Big question: Which deal costs less per gram?
Mathematicians toolbox: I used have I seen a similar problem.
Solve: Firstly, I doubled $3 and 250 so double $3 is $6, and double 250 is 500. So because it has$5 for 500 g and $6 for 500 g it means the cheapest one was $5 for 500 g.
Conclusion: I used the strategy of have I seen a similar problem to get the answer of A.