Talk:Basic Algebra/Introduction to Basic Algebra Ideas/Variables and Expressions

Let's not use "plugging in" as a metaphor for substitution. In a primitive environment, I don't know if it has the same familiarity. Use "put it in" instead.

Heheh, ok, but in a primitive environment, they won't have a computer... unless you are imagining some school in the middle of the african bush which happens to have internet connection and jotters and pencils but no workbooks, which i suppose makes some kind of sense. Can I ask, don't you think we need some kind of video perhaps introducing the topic? --213.217.194.176 13:49, 18 November 2006 (UTC)

Greek letters
I saw in the page that Greek letters are used as names of variables. Maybe it's a good idea to give an overview of the Greek alphabet in appendix or something. Here it is: α alpha β beta γ gamma δ delta ε epsilon ζ dzeta η eta θ theta ι iota κ kappa λ lambda μ mu ν nu ξ xi ο omicron π pi ρ rho ς sigma (end of a word, not used as a mathematical variable) σ sigma τ tau υ upsilon φ phi χ chi ψ psi ω omega


 * I don't think they're commonly introduced at an elementary level. They also aren't used so far in the examples for the first few lessons. I think it would be better to avoid their use altogether for this textbook. Zahlen 03:35, 19 January 2007 (UTC)

Answers in parentheses
Would it not make sense to show the solution for the first couple of problems only, and then to LINK to the solutions? Ideally the link would automatically open a new window (provided the code for that is compatible with simple browsers and low bandwidth).


 * I'm guessing this, or something similar will be implemented in the HSTutorial's static version. I don't think we need to worry too much about formatting for now. Zahlen 03:44, 19 January 2007 (UTC)

Expressions with more than 1 operation and Precedence
Should we be introducing long expressions like 6 x 3 - 4 in this lesson before precedence is introduced in lesson 3? As a mathematician, I'd say no, but I don't have experience teaching such topics to young children. Presently, I've edited the examples and problems so that operators with higher precedence are on the left, i.e no ambiguity arises between evaluating left to right and evaluating in order of precendence.

If we do decide to keep long expressions in this lesson, I think it would be a good idea to break up the evaluation process into steps, e.g. first evaluating 6 x 3 - 4 to 18 - 4, then finally to 14. Zahlen 03:44, 19 January 2007 (UTC)

Game
The lesson links to a game at http://www.quia.com/cm/29771.html. This game uses expressions like 7(9) to mean 7 * 9, which hasn't been taught (yet). We might still want to keep the link, if we can't find better games. (Will HSTutorials be making any games of their own?) Zahlen 04:16, 19 January 2007 (UTC)

Problem with definitions
I was just reading through this material to brush up on my own algebra. I don't know the definition of an expression but the definition here seems flawed to me. First a term is defined and we see that 6/x is one term. Expressions are defined next: "An expression is two or more terms, with operations between all terms.". Yet the list of example expressions starts with "3/4" and "8*n". By the definition of expressions above they are not expressions because they only consist of one term. My belief is that the examples are correct and the definition of expressions is wrong. But on the other hand teaching mathematics is not my field. --Tobbe