# Prealgebra for Two-Year Colleges/Workbook AIE/Properties of multiplication

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## Contents

## Why[edit]

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## Learning Objectives[edit]

- Use the distributive property to estimate products, and then to correct your estimate.
- Find and use patterns in the multiplication table.

## Warm-up[edit]

You have $80 in your wallet. You want to buy 3 DVD's for $19.95 each. (Fortunately, you are in Oregon where there is no sales tax.)

- 1. Approximate the price a DVD to the nearest whole dollar.
- 2. Estimate the cost of the three DVD's.
- 3. Estimate how much money you will have in your wallet after the purchase.
- 4. What do you need to add or subtract from your approximate price of a DVD to get the actual price?
- 5. What do you need to add or subtract from your estimate of the cost of the three DVD's to get the actual cost?
- 6. Exactly how much money you will have in your wallet after the purchase?
- 7. Explain how your estimation and calculation is related to the following application of the distributive property. Be specific about why you are adding or subtracting.

## Activity[edit]

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