What formula would you use to calculate percentage change?

To calculate the percentage change, the formula you would use is (change/original) x 100. This formula works by first determining the change, which is the difference between the new value and the original value. By dividing this change by the original value, you establish how much the value has changed in relation to where it started. Multiplying by 100 then converts this fraction into a percentage, giving a clear representation of the percentage increase or decrease.

For example, if the original value is 50 and the new value is 70, the change would be 70 - 50 = 20. Applying the formula gives (20/50) x 100, which equals 40%. This indicates that the value increased by 40% from the original.

Using the other choices would not yield the correct method for finding percentage change, as they do not accurately reflect the relationship between the change and the original value needed for the calculation.