kitchen table math, the sequel: Saxon bar models

## Monday, July 23, 2007

### Saxon bar models

I was all set to scan in a page from Saxon Math 7/6 when I realized I should search the old site first.

et voila!

Saxon bar models.

large image here

The sad news is that the ktm-1 post gives the exact same problem I'm going to be having C. do tomorrow.

Two years after we did it the first time.

Anyone here think two years might be a tad long between exposures?

This time around we are going to keep at it. We're going to be doing Saxon bar models for fractions, decimals, and percent, and we're going to carry on doing Saxon bar models for fractions decimals, and percent until C. reaches fluency.

Plus we're going to be setting up equations the Saxon way and solving them, and we're going to be doing that, too, until C. becomes fluent at setting up and solving simple equations.

And we're going to do many, many, many story problems.

starter variables in Saxon Math

The Saxon way of setting up equations, fyi, involves using variables that are abbreviations of the unknown you're looking for.

e.g.:

What number is 1/4 of 100?
WN = 1/4 · 100

and:

25 is what fraction of 100?
25 = WF · 100

Saxon also uses WP for what percent. (I'll probably throw in some WDs for what decimal to boot.)

These Saxon "starter variables" are an ingenious way to spare working memory, IMO. Later on, in Algebra 2, he transitions students to x and y when he explains, in a lesson functions & function notation, that x is typically used to represent the independent variable & y the dependent variable.

I did that lesson this weekend; it was a revelation. All these years using x & y -- alongside the concepts of independent and dependent variables -- while having no idea that the two were connected.

Good grief.

Saxon equations with starter variables

#### 1 comment:

Prices said...

"First we'll name the answer y, as in, 'Why do we care?'."

- Hobbes