Overview

The motivating CAHSEE release question for this unit is as follows:

Chris drove 100 kilometers from San Francisco to Santa Cruz in 2 hours and 30 minutes. What computation will give Chris’ average speed, in kilometers per hour?

A. Divide100 by 2.5
B. Divide 100 by 2.3
C. Multiply 100 by 2.5
D. Multiply 100 by 2.3

Major California Content Standards addressed in this unit include:

Mathematical Reasoning (6th and 7th): 1.1 Students analyze problems by identifying relationships, distinguishing relevant from irrelevant information, identifying missing information, sequencing and prioritizing information, and observing patterns.
Algebra and Functions (7th): 4.2 Students solve multi-step problems involving rate, average speed, distance, and time or a direct variation.

Objectives

In Module 4.2 Rate Relationships you will:

  • Deepen your understanding of mathematical concepts, including:
    • Using the relationship D = RT in applied situations, with emphasis on non-matching units
    • Interpreting rate relationships in situations involving quantities other than physical distance
    • Interpreting D=RT relationships graphically as well as algebraically
  • Develop skills in new instructional strategies, including
    • Using dimensional analysis to solve mathematics problems
    • Improving the quality of student explanation
    • Developing students’ ability to use formulas to solve problems