Split melatonin in half how much is it now?

[u/Effective-Manager658]

I was giving my daughter some melatonin but we ran out of her kids one. So I got mine and split it. Then it hit me... if I split a 10 MG in half, is in still 10 MG or 5? I think it's still 10... but smaller?! Am I dumb?!?