Quick-Total

To calculate the final number when you have an initial number and a percentage, you are determining what a specific percentage increase or decrease of that initial number would be. This is often used in contexts like calculating discounts, interest, or growth rates. The formula to find the final number is:

Steps:

1. Identify the Initial Number: This is the original value before any percentage adjustment.
2. Convert the Percentage to a Decimal: Divide the percentage by 100 to convert it into a decimal.
3. Adjust Based on the Percentage:
   • If you are increasing the number by a percentage, add this decimal to 1.
   • If decreasing, subtract the decimal from 1.
4. Multiply by the Initial Number: This gives the final number after applying the percentage.

For example, to find the final value after increasing 100 by 20%, convert 20% to 0.2, then multiply 100 by 1.2 (since 1 + 0.2 = 1.2). The final number is 120. If decreasing, use 0.8 instead (since 1 – 0.2 = 0.8). Thus, the final number is the result after applying the percentage to the initial value.

For example, if you want to find what percentage 25 is of 200, you would divide 25 by 200, yielding 0.125. Then, multiply 0.125 by 100, which equals 12.5%. Thus, 25 is 12.5% of 200. This method is useful in a wide range of applications, from financial analysis to data interpretation.