15 Discount Calculation

How to Calculate a 15% Discount

Calculating a 15% discount involves simple arithmetic. Here's a step-by-step process:

1. Determine the original price of the item you want to purchase.
2. Convert the percentage discount (15%) to a decimal by dividing by 100 (0.15).
3. Multiply the original price by the decimal to find the discount amount.
4. Subtract the discount amount from the original price to get the final sale price.

For example, if an item costs $100, a 15% discount would be $15, making the final price $85.

The Discount Formula

The formula for calculating a percentage discount is:

This formula works for any percentage discount, not just 15%. The key is converting the percentage to a decimal before multiplying.

Worked Examples

Example 1: Calculating a 15% Discount on $50

1. Original price: $50
2. Discount percentage: 15%
3. Discount amount: $50 × 0.15 = $7.50
4. Final price: $50 - $7.50 = $42.50

You save $7.50, and the item costs $42.50 after the discount.

Example 2: Calculating a 15% Discount on $200

1. Original price: $200
2. Discount percentage: 15%
3. Discount amount: $200 × 0.15 = $30
4. Final price: $200 - $30 = $170

You save $30, and the item costs $170 after the discount.

Example 3: Calculating a 15% Discount on €100

1. Original price: €100
2. Discount percentage: 15%
3. Discount amount: €100 × 0.15 = €15
4. Final price: €100 - €15 = €85

You save €15, and the item costs €85 after the discount.

Common Mistakes

When calculating discounts, it's easy to make a few common errors:

• Adding instead of subtracting: Remember, the discount reduces the price, so you subtract the discount amount, not add it.
• Using the wrong decimal: Always divide the percentage by 100 to get the correct decimal. For example, 15% is 0.15, not 1.5.
• Rounding too early: Perform all calculations before rounding to the nearest cent or currency unit.
• Applying multiple discounts incorrectly: If multiple discounts apply, calculate each one sequentially on the remaining price.