Class 11, October 8, 2015 Lessons 2.4 & 2.5

 By the end of this lesson, you should understand: ◦ The scale on graphs can change the perception of the information they represent ◦ To fully understand a pie chart, the reference value must be known

 By the end of this lesson, you should be able to: ◦ Calculate relative change from a line graph ◦ Estimate the absolute size of the portions of a pie chart given its reference value ◦ Use data displayed on two graphs to estimate a third value

 Main idea: ◦ It is important to ask questions about and make sense of data  Main idea: ◦ In all relative measures, be aware of the reference value

 By the end of this lesson, you should understand that: ◦ A relative change is different from an absolute change ◦ A relative measure is always a comparison of two numbers

 By the end of this lesson, you should be able to: ◦ Calculate a relative change ◦ Explain the difference between relative change and absolute change

 Main idea: ◦ Relative and absolute change can be difficult to interpret when describing quantities expressed as percentages ◦ Refer to the statements prepared in Questions 2 and 3. Why is the absolute change so different when the relative change is the same? ◦ How are Questions 2 and 3 in this lesson alike or different from Questions 1 and 2 in Lesson 2.3, in which you found the absolute and relative change in populations?