For example, say you’re trying to figure out how much your income increased from one year to the next. If you made $37,000 last year and $45,000 this year, subtract 37,000 from 45,000, which is 8,000. Alternatively, in the world of retail, when a product receives a discount, this is often expressed as the product being “x% off” which is a percent decrease. If a pair of pants was previously sold for $50 and is now sold for $30, $50 is the original value and $30 is the new value. To start, subtract $50 from $30, which is -$20.
Continuing the example, divide 8,000 (the difference between your incomes) by 37,000 (which is the original value). The answer is 0. 216. Alternatively, dividing the difference (-$20) by the old value ($50) is -0. 40. Another way of thinking of this is that the $20 change in value is 0. 40 of the $50 starting point, and that the change of value was in the negative direction.
Take 0. 216 and multiply it by 100. In this case, the answer is 21. 6, so your income increased by 21. 6%. Alternatively, to get the final percentage, multiply the decimal answer (-0. 40) by 100. -0. 40 × 100 = -40%. This means that the new price of $30 for the pants is 40% less than the old price of $50. In other words, the pants are 40% off. Another way to think of this is that the $20 difference in price is 40% of the initial price of $50. Since this price difference results in a lower final price, give it a negative sign.
For instance, say you’re trying to figure out how much a school’s enrollment changed between years. If the enrollment for this year is 12,125 and it was 13,500 last year, take 12,125 away from 13,500, which is 1,375.
In this case, divide 1,375 (the difference between the numbers) by 13,500 (the original value), which is equal to 0. 1019 (when rounded).
Multiply 00. 1019 by 100, which is 10. 19. So, enrollment decreased by 10. 19%.
