So I was helping my 9 year old SEI nephew with his math wordbproblems and we came to one that expressed this dichotomy well. The question was "Ted made 100 dog and cat treats. How many dog treats did he make?"
My answer and first inclination was "well, it doesn't say what percentage of the 100 was for the dogs"
He responded qwith "we don't know because it doesn't tell us how many of them were for the cats"
You can tell a lot by how people approach problem solving.