Education Technology

Taxes & Tips

Published on 08/13/2010

Activity Overview

In this activity, students will increase their understanding of the use of the formula T = r × p, which is encountered both in the real world and in the typical Algebra 1 class. They will calculate the amount of taxes and tips exactly, and then use estimation.

Key Steps

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    In this activity, students will explore the taxes and tips percentages commonly used in stores and restaurants. They will first develop the pattern of converting a percent to a decimal.

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    Then students will use the dynamic tax equation model to calculate the tax on several items given in a spreadsheet. They will compare the difference of calculating the taxes on individual items, then summing to the calculating the sum of the item prices multiplied by the tax rate.

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    Students will finally use mental math estimation to calculate 15% or 20% of a restaurant bill or calculate the tax on a high priced item. They will compare their estimation to the actual answer.