40% off $200 = $120. You save $80.
Equation: $200 − (40% × $200) = $200 − $80 = $120.
Another way to read it: you pay 60% of the original price — that's $120.
$120. The discount is $80 and the final price you pay is $120.
You pay $120 (before tax). That's $200 minus a $80 discount.