Can you check the math on this? (Details)

I took a part time job. When credit cards are run at the end of the night and my tips are determined, my boss requires me to give him 3% back on those tips for the swiping of the card charge. I’m terrible at math, but it seems off somehow. Can someone help correct my logic?

Here’s how I see it, and maybe I’m off, I really don’t know.

Say I have $100 in tips, for easy math. So the swipe fee is $3. I give him that $3 and am left with $97. But the original amount in actuality with the 3% charge is $103, is it not? When I give him $3 and walk with $97, doesn’t that total $6?

Is his request fair? Does the math work out, or is he kind of making money on the deal?

Thanks in advance.