To calculate the percentage of a number, multiply the number by the percentage and divide by 100. For example, to calculate 20% of 100, multiply 100 by 20 and divide by 100. The result is 20.

Percentage change

To calculate the percentage change from one number to another, subtract the first number from the second number, divide the result by the first number, and multiply by 100. For example, to calculate the percentage change from 100 to 120, subtract 100 from 120 to get 20. Divide 20 by 100 to get 0.2. Multiply 0.2 by 100 to get 20. The result is 20%.

Base number

To calculate the base number, multiply the percentage by the number and divide by the percentage. For example, to calculate the base number of 20% of 100, multiply 20 by 100 and divide by 20. The result is 100.

Percentage of a number

To calculate the percentage of a number, multiply the number by the percentage and divide by 100. For example, to calculate 20% of 100, multiply 100 by 20 and divide by 100. The result is 20.