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Overview
CAEC Math
Number Sense
5. Financial Mathematics: Solving Problems with Fractions, Decimals, and Percentages
5.10 Best buys with discount
Best Buys with Discount
Find out how to calculate sale prices and compare discounted unit prices so you can identify the true best buy, not just the biggest percent off.
What You'll Learn
Calculate a sale price using \( P_{sale} = P_{original}(1 - d) \), where \( d \) is the discount rate as a decimal.
Recognize that a bigger percent discount does not always mean the lower final price.
Convert each discounted price into a unit price with \( U = \dfrac{P_{sale}}{q} \) before comparing.
Compare unit prices across different package sizes and discount rates to find the true best buy.
Apply the same method to coupons, buy-one-get-one deals, and multi-item discounts.
Check answers by estimating with rounded numbers before doing exact decimal calculations.
This Unit Includes
Learning resources
TEST-PREP Curriculum Aligned