Huh??
Dagi, the numbers on the clippers that the barber used on Gary's hair have numbers. The larger the number, the longer the hair. So when he says they used a 5 on the top and a 3 on the sides, he's saying he got a style with the top longer than the sides and back.
I always tell the stylist to give me a #1 all around, so it's very very short, crew cut style.