It’s 7 times 70 if I remember correctly, which according to my calculations is 490. But to be fair, there is a certain context to it. Forgiveness does not mean allowing someone to sin or do you wrong, it just means don’t repay in like kind. If we’re only nice to those who are nice to us, and cruel to those cruel to us, what good is it? That’s what everyone does, and requires no effort. It’s the unexpected that can have profound consequences.
It’s a valid thing to call upon the powers that God has duly established (Romans 13).
Way to late for me to be doing math, obviously. But that verse does say that if a person comes to you and asks for forgiveness you are to forgive him 7 times 70. So that verse is saying they must ask. But there are instances all through the Bible of people being forgiven without asking.
On another note, I believe the “turning the other cheek” doesn’t mean to let the guy slap you again. I believe it means we are to walk away from the fight.