A gaming machine and method for operating a slot machine game in which virtual or mechanical reels include numbers from which a prize amount is produced by concatenation. In response to a wager activation by a player, the reels display conduct a base game including spinning the reels and stopping to produce a respective randomly selected outcome having a plurality of symbols including single digit numbers which are positive numbers and zero, double digit numbers which are positive and double zero, and blank symbols. A prize amount associated with the outcome is identified by concatenating the single and double digit numbers and ignoring the blank symbols along a designated payline.