As soon as I read that problem my brain went on instinct and quickly calculated you need 3 vans and 2 cars. And somehow I'd skipped over the part that implies you need the number of vehicles to total five.<p>But I guess I'm just wired like that. And one thing I'm getting out of this how-do-we-teach-math kerfuffle is, people who are "just wired like that" think differently from the people who most need to learn math. Paul Lockhart would advocate dropping the pretense of real-world relevance altogether: "Suppose I were thinking of groups of five and seven things (as I very often am). How would I divide 31 things into groups of five and seven with none left over? It's the <i>beauty</i> of solutions to problems like this, which exist purely of and in the imagination, that we are denying today's children!"