Can someone please explain

Guys I need some help please;

I'm new to crypto investment and I've been watching some tutorial series to learn the basics.

I just bought £50 of bitcoin from Coinbase and deposited it into GDAX (to avoid fees when sending to an exchange). I confirmed that I received about 0.005...% of the bitcoin. I then sent that entire amount into Binance and only received 0.0002% in there.

Can someone please explain what I did wrong there and how the fees work when sending from gdax to binance? Thanks