It is on the back of the ticket below the barcode. For the $2M Holiday Tickets, you will see 1292 (which is the game number), then 0106648 (that is the roll number) and then a random serial number (0 through 9) and finally the ticket number.
For the $2M Holiday tickets I bought today, the ticket number on the back was 1292-0106648-2-030. The roll numbers for a typical scratch off game start at 1,000 and is sequential for the entire distribution of a game. When the game is new, the roll numbers are low and as more tickets are sold, the numbers get higher and higher until they are sold out.
The reason I am asking EMT Adam about the serial number for the roll is that if his winning ticket was on roll number 110,000 for example, that would mean he likely won the second $2M prize and I wouldn't buy any ticket with a serial number above 60,000. However the opposite is true as well. If his number was 40,000, I would focus any ticket purchases on roll numbers above 60,000. The total ticket distribution for this game was 104,000 tickets. The reason there is about 114,000 rolls is that the lottery skips numbers in between rolls and that makes the roll count appear a little higher.
There is still the possibility of a second $2M prize. However, I don't want to buy tickets in the wrong distribution group. I'm on the fence as to whether i'll still focus on the $2M holiday ticket. I am still looking at the $200MS and Super Millions. I suspect the last prize in the Super Millions will be won within the next month as the supply disappears. Only 2.5% of the total tickets remain in circulation. The reason I prefer the $2M holiday game and the $200MS is that they are both cheaper tickets. The greatest risk with the $200MS is that one or both of the top prizes may have been trashed or returned to the lottery office because of the age of the game.