Algebraic Notation
when a number is not a number
when a number's a letter
Letters and Numbers

To get to grips with letters and numbers one needs to know their BIDMAS and BODMAS. Knowing your powers orders and indices is also important. And working with the order of operations, numeracy speeds things up, especially in a classroom (crowd, rabble, troop, group, melee).

We also need to know our fractions, and how to write fractional terms. We usually lose the multiplication sign (the division sign went out with the numerator and the denominator).

We get into topics like simplification, changing the subject, and sometimes as teachers we are trapped into easy methods (e.g. change side - change sign) that lose the understanding. Q. What is the point of doing something without the understanding? A. In order to pass exams and get good grades.