First breed the Medicham with a Female member of the Machop line. The Kid should be have Ice Punch. Level it up the MALE Machop until it Learns Cross Chop. Remember that you have to Keep Ice Punch.
Breed this Male with a Female ElectaBuzz. Bingo the kids should know both moves.
All this information is on the Pokédex of this site: http://www.serebii.net/pokedex-dp/