After I've taught the concept we practice using the following rules.
Have 3 students come up to the front of the room and stand side by side with arms length of distance between them. Then, the 2 students on the ends of the line hold up numbers. (Sometimes I write them on small wipe off boards or sometimes I write numbers on paper.) The center student is the alligator. We all sing the alligator song and then the when we say "Chomp" the alligator turns to the student with the largest number and with arms extended, < , chomps their arms down. To keep the rest of the class on task they do mini chomps in that student's direction. They have some much fun with this and in the end they remember the hungry alligator's mouth always open faces the largest meal (number).