Their performance was videoed on Friday, and the video will be uploaded to the competition site.
The school has been part of the Fonterra scheme for two years, Mrs Moorhouse said, and getting the milk has been good for the children. The tetrapacks are kept in a fridge and given cold, and they can drink the milk whenever they want.
"It tops them up. They're not hungry."
Many of the children come from dairy farms, and wear gumboots to school. Milk is familiar to them.
Apart from water, it's the only drink they are allowed to have at school.
When the tetrapacks of milk are empty they are flattened, folded and sent away for recycling. The end products are used to make things like roof tiles and exercise books for people in other countries.