1. Estimation, Graphs, and Mathematical Models
1.2 Notes
Estimation, Graphs, and Mathematical Models

2. Warm-up: Rounding Round the World’s Population
The population here on planet Earth when the book was authored was 6,751,593,103 people.
Round the world’s population to the nearest million.
Round the world’s population to the nearest thousand.

3. Rounding
General Rule: Look to the place value to the right of what you want to round to. If it’s 5 or higher, you round up the place value. If it’s less than 5, the place value holds.
Round pi to the nearest hundredth.
Round pi to the nearest thousandth.

4. Applying Estimation Techniques to a Circle Graph
Use a circle to represent the whole and divide it into sectors proportional to their part of the whole.
According to the U.S. Census Bureau, in 2008, there were 220,948,915 Americans 20 years and older. Assuming the circle graph is representative of this age group,
a. Determine a calculation that shows the number of Americans 20 years and older who define old age by a decline in physical ability.
b. Use rounding to find a reasonable estimate.

5. Bar Graph: Make a Prediction

6. 1.2 HW
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