## What is a percent?

Percent implies “for every single 100” or “out of 100.” The (%) icon as a fast method to compose a portion with an of100 As an instance, as opposed to claiming “it drizzled 14 days out of every 100,” we claim “it drizzled 14% of the moment.”

Portions can be composed as decimals by relocating the decimal factor 2 locations to the left:

Decimals can be composed as a percents by relocating the decimal factor 2 locations to the right:

## Formula for computing portions

The solutions for computing portions or for transforming from portions are reasonably easy.

To transform a portion or decimal to a percent, increase by 100:

To transform a percent to a portion, divide by 100 as well as lower the portion (ideally):

### Examples – Percentage Increase and Decrease

**In January Dylan worked a total of 35 hours, in February he worked 45.5 hours – by what percentage did Dylan’s working hours increase in February?**

To tackle this problem first we calculate the difference in hours between the new and old numbers. 45.5 – 35 hours = 10.5 hours. We can see that Dylan worked 10.5 hours more in February than he did in January – this is his **increase**. To work out the increase as a percentage it is now necessary to divide the increase by the original (January) number:

**10.5 ÷ 35 = 0.3 **

Finally, to get the percentage we multiply the answer by 100. This simply means moving the decimal place two columns to the right.

**0.3 × 100 = 30**

**Dylan therefore worked 30% more hours in February than he did in January.**

In March Dylan worked 35 hours again – the same as he did in January (or 100% of his January hours). What is the percentage difference between Dylan’s February hours (45.5) and his March hours (35)? You may think that as there was a 30% increase between Dylan’s January hours (35) and February (45.5) hours that there will be a 30% decrease between his February and March hours. This assumption is incorrect – let’s calculate the difference.

First calculate the decrease in hours, that is: **45.5 – 35 = 10.5**

Then divide the decrease by the original number (February hours) so:

**10.5 ÷ 45.5 = 0.23** (to two decimal places).

Finally multiply 0.23 by 100 to give 23%. **Dylan’s hours were 23% lower in March than in February.**

Sometimes it is easier to show percentage decrease as a negative number – to do this follow the formula above to calculate percentage increase – your answer will be a negative number if there was a decrease. In Dylan’s case the decrease works out at -15.5. -10.5 ÷ 45.5 = -0.23. -0.23 × 100 = -23%.