somebody said they will give me 10% back when i purchase the jeans which are $122. how much money is that?

Ten percent of $122 is $12.20. Good luck. I was a college professor.

$122*.10 = $12.20

122/10 = 12.2

How are you going to pay for something that expensive if you can't do simple math...?

12.20

$12.20 (122 x .10) if you wanted to know what 20 percent of it was, you'd multiply it by .20, and so on.