posted by kayla .
i am in 4th grade doing my sisters homework don't ask why but i need help on this question.
-- Explain why the cost of an item discounted 20% can be calculated by multiplying the original price by 0.8
100% - 20% = 80% = 0.8
When an item says it's 20% off, then the new price is 80% of the original price.