First you need to turn the percentage 120% to a decimal. To turn a percentage to a decimal, you simply divide said percentage to 100, or simply just move a decimal point two places to the left and drop the % sign.
120/100 = 1.2 120 -> 12.0 (1 move)-> 1.2 (2 move)
Now all you need to do is multiply 1.2 and 320. This gets us 384.
