7th Grade Sales Tax and Discount Worksheet Answer Key

To solve problems involving percentage changes in prices, focus on the basic formulas: multiplying the price by the percentage and adjusting accordingly. For instance, to calculate an increase, multiply the original amount by the percentage, then add the result to the original price. If the value is reduced, multiply the price by the percentage and subtract the result from the original.

For example: If a product costs $50 and the adjustment is 10%, calculate 10% of 50 by multiplying: 50 * 0.10 = 5. Then, add or subtract that amount from the original price depending on whether it’s an increase or decrease. If it’s an increase, $50 + $5 = $55. For a decrease, $50 – $5 = $45.

It’s also useful to double-check your work with reverse calculations: After adjusting the price, verify by calculating what percentage of the new price the difference represents. This ensures accuracy and understanding of the concept.

Use this method with various percentages to improve your ability to handle similar calculations efficiently. Mastering these skills will aid in real-life scenarios like budgeting, shopping, or any situation where percentages come into play.