How to Find the Percentage Decrease
Finding percent decrease is similar to finding the increase, but the formula is a little different. This video demonstrates this using three examples. To find the percent decrease in the numbers 3.6 and 2.0, take the first number, subtract the second number from it, and divide this by the first number: 3.6-2.0 ÷ 3.6 = 1.6/3.6 which simplifies to 4/9. The percentage equivalent is 44.4%.
Finding percent decrease for a pair of numbers is very similar to finding percent increase, but the formula is a little bit different. Once again I’ll demonstrate on three different types of number pairs. First decimals then fractions then dollar amounts.
In the first example we have 3.6 And 2.0. To find percent decrease we’ll take the first number, subtract the second number, and divide by the first number. So what we have is 3.6 minus 2.0 over 3.6. We can simplify this by subtracting 2 from 3.6 and we get 1.6 over 3.6.
Now if you reduce this fraction what you wind up with is 4 over 9 whose percentage equivalent is 44.4 percent. In the second example we have 5 over 6 and 2 over 3. Once again we’ll take the first number, minus the second number, over the first number.
Now we don’t have a common denominator yet, but we can convert the second number to denominator of 6 and then we’ll have. So multiply this by 2 over 2, and what we wind up with is 5 over 6 minus 4 over 6 divided by 5 over 6.
Now 5 over 6 minus 4 over 6 is just 1 over 6, so what we have is 1 over 6 divided by 5 over 6 or 1 over 6 times 6 over 5. Now the 6’s cancel here and what we’re left with is just 1 over 5 the percentage equivalent for 1 over 5 is 20 percent.
In this final example we have two hundred and thirty, two hundred dollars and thirty dollars. So we’ll take once again the first number, minus the second number, divided by the first number. 200 minus 30 is 170. So what we have is 170 over 200.
Since our denominator is already so close to 100 we’ll just convert it to 100 and then we’ll have our percentage figured out already. So we’ll divide top and bottom by 2, 170 over 2 is 85, and 200 over 2 is 100. So what we have is 85 over 100 which by definition is 85 percent.