A few basic goals of high school mathematics will be looked at closely in the top programs chosen for high school by the state of Washington. Our concern will be with the mathematical development and coherence of the programs and not with issues of pedagogy.
Algebra: linear functions, equations, and inequalities
We examine the algebraic concepts and skills associated with linear functions because they are a critical foundation for the further study of algebra. We focus our evaluation of the programs on the following Washington standard: A1.4.B Write and graph an equation for a line given the slope and the y intercept, the slope and a point on the line, or two points on the line, and translate between forms of linear equations.
We also consider how well the programs meet the following important standard: A1.1.B Solve problems that can be represented by linear functions, equations, and inequalities.
Linear functions, equations, and inequalities in Holt
We review Chapter 5 of Holt Algebra 1 on linear functions.
The study of linear equations and their graphs in Chapter 5 begins with a flawed foundation. Because this is so common, it will not be emphasized, but teachers need to compensate for these problems.
Three foundational issues are not dealt with at all. First, it is not shown that the definition of slope works for a line in the plane. The definition, as given, produces a ratio for every pair of points on the line. It is true that for a line these are all the same ratios, but no attempt is made to show that. Second, no attempt is made to show that a line in the plane is the graph of a linear equation; it is just asserted.
Third, it not shown that the graph of a linear equation is a line; again, it is just asserted.
| Newsletter signup | Send us your ideas