If someone stole $100 from register and return 5 mintues later to purchase $70 worth of item and i give them $30 in change how much money did i loose?

You lost $40 because you have to subtract 30 from 70

I think it would be $60.
If you had $500 for example and you lost $100 you would have $400.
Then you get $70 back so you now have $470.
Then you give away $30 so you have $440.
$500-$440 is $60

820,000 is the answr