I need to work on the basics.
I gave a quiz last week, with 10 multiple choice questions. Many of them had questions about the correlations and the correlation coefficient. Those didn't surprise me. What did surprise me what the question asking "Which of these is an example of an algebraic expression?" Most of the class picked choice 1) y = mx + b.
I had to ask them today about expressions and equations, and they seemed to know the difference. So I wrote y = mx + b on the board and asked what that was. They looked at me oddly, as if it were a trick question. Testing jitters? I don't know.
At least, no one picked the inequality, and no one picked the Pythagorean Theorem. But too few people picked the expression.
For those playing along at home, an expression doesn't have an equal sign and can't be "solved". It can only be "evaluated" if you know the values of all the variables. (Moreover, it doesn't actually have to have any variables or parentheses or operators. "6" is an expression.)
As for my students, their expressions were "puzzled" and "bewildered". Mine was more "disappointed".
We're working on it.