Flesch Kincaid readability measures are all over the board.  Results are similar to those found via the Fry graph.  This supports my premise that it is difficult to measure readability of math books.  Nonetheless, they are difficult for most students to read.

SAMPLE 1

We now find a formula for the distance d(A,B) because two points A(x1,y1) and B(x2,y2) in the plane. Recall from Section P2 that the distance between points a and b on a number line is d(a,b)=|b-a|. So from Figure 4 we see that the distance between the points A(x1,y1) and C(x2,y1) on a horizontal line must be |x2-x1|, and the distance between B(x2,y2) and C(x2,y1) on a vertical line must be |y2-y1|. The Distance Formula We now find a formula for the distance d(A,B) because two points A(x1,y1) and B(x2,y2) in the plane. Recall from Section P2 that the distance between points a and b on a number line is d(a,b)=|b-a|. So from Figure 4 we see that the distance between the points A(x1,y1) and C(x2,y1) on a horizontal line must be |x2-x1|, and the distance between B(x2,y2) and C(x2,y1) on a vertical line must be |y2-y1|.

SAMPLE 2

Your text: Discovery Project Visualizing Data

When scientists analyze data, they look for a trend or pattern from which they can draw a conclusion about the process they are studying. It is difficult to find hidden patterns in lists of numbers. But a graph of the data can efficiently reveal any hidden pattern. In this project we examine data obtained by a biologist on the levels of three different enzymes in blood samples taken from expectant mothers. You can find the project at www.stewartmath.com. Discovery Project Visualizing Data When scientists analyze data, they look for a trend or pattern from which they can draw a conclusion about the process they are studying. It is difficult to find hidden patterns in lists of numbers. But a graph of the data can efficiently reveal any hidden pattern. In this project we examine data obtained by a biologist on the levels of three different enzymes in blood samples taken from expectant mothers. You can find the project at www.stewartmath.com.