Here is a pretend number pad for kids to practice their lunch numbers on. I usually give these out at the beginning of the year with the students' numbers written at the bottom. I ask them to practice punching in the number for about 5 minutes before lunch everyday until they memorize their number. They catch on pretty quickly and it is easy for us to get through the lunch line!
Black & White and Color versions included. PDFs and Word Docs also included in case you need to change the order of the numbers to match your cafeteria's system.