Those aren't "millions of bitcoins", that's only 330k+ BTC. Electrum is showing you the units in millibitcoins.
He needs to know about Bitcoin units as well as how to customize display of Bitcoin unit in Electrum wallet.
Setup Electrum [Guide].
It's simple, and in Electrum wallet, do this.
Tools > Preferences > Appearance and changing the Base unit to either of following available units: BTC, mBTC, bits, sat.
Bitcoin has more units than that.
[Did you know?] Bitcoin Table of Units