This tool enables you to add 15 percent to a certain value.
When can it be interesting to increase a number by a percentage? This is useful for a salary increase, for example. You want to calculate what your future wage will be. You can also hear through the media that a certain product will become more expensive in the future (for example, the price of gasoline). Then you can calculate here what the new price will be. Another example is that a company decides that production should increase by a certain percentage by next year. Here you can calculate exactly how many more items will be produced.
If you want to add P percent to a number Y, you can use this formula:
result = Y + (P/100*Y)
For example add 15 percent to 60: result = 60 + (15/100*60) = 69