How many times can you subtract 2 from 21?

You can subtract 2 from 21 a total of 10 times. This is because each time you subtract 2, you are left with 19, and you can repeat the process until you reach 1. Mathematically, this can be represented as 21 - 2 = 19, 19 - 2 = 17, and so on until you reach 1.