Numberjacks - Series 1 - The Cuck-cuck-cuck-oo-oo-oo Bird

Comedy adventure series, aimed at four and five-year-olds, in which animated numbers solve mathematical problems in the real world, with input from real children. 0 has disappeared, and is causing things to disappear into nothing. When 3 helps out on the Brain Gain machine everything is tripled, but order is finally restored and 6 and 0 are returned to base.