Adding percentage to a cell value

Sorry to ask a simple question folks. Cell J10 has a numeric value, I need to add 20% to this figure into cell J12. Help please, thanks

Go to cell j12
Press =
Use the mouse to click on cell j10
Type in the following *1.2
Press enter

A little confused why 1.2 = 20%, but thank you.

If you want to know what 20% of the valueis then just do *0.2. But if you want to know what 20% more than the starting value is, then you need to take the starting value 100% plus 20% which is 120% of the starting value, which is 1.2 times