I've noticed the same thing in all the school curricula I've seen. The word problems are often vague, and all to often completely ambiguous. They require guessing what the question writer had in mind when she wrote the question, which are usually unstated assumptions that apply only to the way math is done in schools. This is not the way to teach the kind of precise thinking and careful definition of terms that one needs to understand why math is the way it is: the “study of precisely defined objects.”
Teachers, if you want your pupils to understand how to create a mathematical problem from a description of a practical one, you must train them first to state the situation with absolute precision and without ambiguity. The best way to do that is, as in the teaching of all virtues, to fastidiously follow that habit yourself. That the questions in math textbooks fail to do that so often is another sign of the enormous institutionality of our education problems.
Teachers, if you want your pupils to understand how to create a mathematical problem from a description of a practical one, you must train them first to state the situation with absolute precision and without ambiguity. The best way to do that is, as in the teaching of all virtues, to fastidiously follow that habit yourself. That the questions in math textbooks fail to do that so often is another sign of the enormous institutionality of our education problems.