Reading your response, I realized the formulation of the question forces the student to deal with not only icons or only numbers, but rather they have to deal with both. That is, they see five pennies, and see one cup. But, they need to reason the 1 cup can hold 6 pennies, then perform the calculation. It seems the strange part of the problem - that it mixes icons and numbers - might precisely be why it was formulated as such.

There are even more abstractions that need to be dealt with than that - they have to associate the cup that can hold 6 pennies is what is considered to be 'whole', and they need to recognize the 'missing' part will exclude 'part I know'. Whether this is a sound approach or not, I don't know - but I can understand, it being so different from traditional mathematics, it would ruffle some feathers.