Core-plus Mathematics Course 3 Unit 4 Answer Key

Core-Plus Mathematics: Course 1, Unit 1, Lesson 4 Review

The last lesson of the Unit 1, "Looking Back"

Whew, we learned so much in the previous three lessons that we need a whole review lesson, this is the Core-Plus way. Finally the book gives the name to the "rules", that is, "strategies" that were presented before:

In mathematics, relations like these — where each possible value of one variable is associated with exactly one value of another variable — are called functions.

Yay! At least something that looks like real mathematics. This definition does not work for reciprocal function, which is not defined for input value of 0, but we are going to let this one slide and leave the notions of range and domain for a next lesson.

The textbook st i ll peddles "spreadsheets, computer algebra systems, and graphing calculators to answer questions about functions" instead of teaching symbolic methods of working with them.

The chapter includes a "real world" problem about borrowing from a bank at just 0.5% interest and a fixed monthly payment. The textbook asks "what the park owes the bank at the end of each of the first 12 months", but as before, no attempt is made to derive a symbolic rule to find the result. Instead, the textbook suggests using either a graphing calculator or a computer.

At the end of this short chapter the book goes completely superficial, suggesting the following problem:

[The ride owners] were unsure about just what that price should be. They decided to do some market research to get data about the relationship between price per ride and number of riders that would be expected each day. Complete a table that shows how you believe the number of riders will depend on the price per ride. Explain the pattern of entries you make and your reasons for choosing that pattern.

WTF? The managers were not sure about the pattern. They decided to do a market research. Now the book wants students to figure out what some Joes and Janes would answer, and then explain their motivation? This is some deep math right here.

The chapter ends with a super-complicated task to match picture to formula, no need to calculate anything. Deep, deep math.

With this, the first unit ends. Good luck learning, kids, you will need it.

In the next lesson: Exploring distributions — actually some useful stuff about making sense of a bunch of data points, but presented in the usual incoherent manner.