Skill: percent-applications

Percent Applications Lab

Slide the price, the discount, and the tax — then run the successive-discount experiment and discover why two 20%-offs are NOT 40% off.

1 Discount + Tax Playground

Move the sliders and watch the register tape update. Discount always comes first; tax applies to the sale price.

Discount ()

Sale price

Tax ()

Total due

Price $80

Discount 25%

Sales tax 8%

Try the classic trap: does raising the tax slider change the discount? (It should not — discount comes first.)

A $100 item gets two successive discounts. Is that the same as one big discount?

Start$100.00

After first discount

After second discount

First discount 20%

Second discount 20%

Set both to 20%: the final price is $64, not $60. Two 20%-offs = one 36%-off.

For challenges 1–2, set the sliders first, then press Check. Challenges 3–4 ask you to type a prediction first.