1) Do you agree with Isabelle and Doug's thinking?
Isabelle and Doug used fractions to express their reasoning. Comparing fractions is the best way to find the answer.
2) Is Isabelle and Doug's strategy accurate?
Doug is right because he's comparing the number of cups contracted against the total. Isabella is not correct because she is comparing part against part.
3) Did Isabelle and Doug answer the question?
No, they did not answer the question because they need to compare all the containers and are only looking at container B