If I am willing to buy 100 shares at $100, I may be willing to buy 300 shares at $60. So just because my bid got filled doesn't mean I won't be buying more.
100 shares at $100
200 shares at $60
This will satisfy your demand position.
I would still enter two bids; it's just a matter of adjusting how many at each level.
All the shares in the auction are sold at the same price. If the market clears at 60, a person entering the bids I described would buy 300 shares at 60.