With the card slot lit up he knew how to get started finding his balance with what?\nOptions:\n- slot machine\n- ticket machine\n- bank machine\n- telephone\n- automated teller
Let's think step by step.
automated teller
An automated teller can be used to find balance.

The card slot lights up in an automated teller.

An automated teller is a machine.

.

So, the final answer is automated teller