Students should be describers. Many people claim that mathematics is a language.
If so,it is a superset of ordinary language that contains extra constructs
and symbols,and it allows you to create,on the fly,new and expressive words and
descriptions. Students should develop some expertise in playing the mathematics
language game. They should be able to do things like:
• Give precise descriptions of the steps in a process. Describing what you
do is an important step in understanding it. A great deal of what’s called
“mathematical sophistication” comes from the ability to say what you mean.
• Invent notation. One way for students to see the utility and elegance of
traditional mathematical formalism is for them to struggle with the problem
of describing phenomena for which ordinary language descriptions are much
too cumbersome (combinatorial enumerations,for example).
• Argue. Students should be able to convince their classmates that a particular
result is true or plausible by giving precise descriptions of good evidence
or (even better) by showing generic calculations that actually constitute
proofs.
• Write. Students should develop the habit of writing down their thoughts,
results,conjectures,arguments,proofs,questions,and opinions about the
mathematics they do,and they should be accustomed to polishing up these
notes every now and then for presentation to others.
Formulating written and oral descriptions of your work is useful when you are part
of a group of people with whom you can trade ideas. Part of students’ experience
should be in a classroom culture in which they work in collaboration with each