Yes, if increasing order size the order is split and tagged on at the end of the queue in most systems.
Didnt always use to be that way. A few years back there was a huge rort on some order entry systems of placing small orders at multiple levels just in case you wanted them later, and then just expanding them on the opening/closing etc auctions if 'the price was right'... and RETAINING you place in the queue! Was also used for trading halts.
Of course when the pigeons cottoned onto it the 'loophole' was closed.
