Parsing algebraic expressions is always a pain. If you need to compute, say, 2+4*2, the answer should be the same as (2 + (4 *2)), not ((2 + 4) * 2) — in other words, the right answer is 10, not 12.

In algebra, letters are used to stand for values that can change (variables) or for values that aren’t known (unknowns). A term is a combination of letters and/or numbers, often multiplied together, ...

A mathematical proof is a sequence of statements that follow on logically from each other that shows that something is always true. Using letters to stand for numbers means that we can make statements ...