Percentage increase is one way to show how two totals compare -- the percentage increase shows how much larger a final amount is from the initial amount. You can calculate percentage increase using two different methods that compare the initial and the final quantities of a number.

## Subtraction Method 1: Calculate Change

In the subtraction method, you first **calculate the amount of change between the initial quantity and the final amount. Subtract the initial total from the final total to find the change**.

Say you had 105 sheep last year and 127 sheep this year. To find the change, you subtract 105 and from 127:

**127 - 105 = 22**

So, the total of sheep you have has increased by 22 sheep. Note that if you get a negative number when you subtract the initial total from the final, you're dealing with a percentage *decrease* instead.

## Subtraction Method 2: Divide and Multiply

Now, you **divide the change by the initial total.** This will give you a decimal number. Your total changed by 22 sheep, and your initial number of sheep was 105. So, divide 22 by 105:

**22/105 = 0.209**

**Multiply 0.209 by 100 to get the percent change**:

**0.209 x 100 = 20.9 percent**

So, the number of sheep you have increased by 20.9 percent since last year. Note that if you get a negative percentage using this method, then your total has *decreased* by that percent, rather than increased.

## Division Method 1: Divide New by Old

In the division method, you don't calculate change through subtraction. Instead, you first **divide the final total by the initial total.** Say you ate at 43 restaurants last year and at 57 restaurants this year. You want to find the percent increase. You divide 57 by 43 to produce a decimal number:

**57/43 = 1.326**

So, your first step produces a result of 1.326.

## Division Method 2: Convert to Percentage and Subtract

Now, **multiply the decimal number by 100, and then subtract 100 from the product of this multiplication.** You got a result of 1.326 when you divided your new total by your initial. Multiply by 100:

**1.326 x 100 = 136.6**

Now, subtract 100 from this total to find the percent increase:

**136.6 - 100 = 36.6 percent**

So, the number of restaurants you ate at this year increased by 36.6 percent from last year. If the total you get from this method is negative, then it is a percent *decrease* rather than a percent increase.

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