Emily is buying a box of cereal that costs $4.29. She has a coupon for $0.55 off, and the store doubles the coupon. How much does she pay for the cereal?

1. Doubling the coupon means the discount is twice its face value: 2 times 0.55 equals 1.10 dollars off. 2. Subtract the doubled discount from the shelf price: 4.29 minus 1.10. 3. Line up the decimal points: 4.29 minus 1.10 equals 3.19. 4. Emily pays $3.19 for the cereal. 5. Taking only $0.55 off gives $3.74, which ignores that the store doubled the coupon. _Source: OpenStax Prealgebra (CC BY 4.0), Ch 5 "Decimals", section 5.2 Decimal Operations_