KAI - method for brushing teeth is taught in kindergarten, sometimes in combination with rhymes. Teeth are first brushed at chewing surface (Kaufläche), then outside and inside surfaces (Außen + Innen).
KAI + E means parents (Eltern) are brushing over after children are done.
After a while, children switch to circular movements and jouncing 45 degree movements (so called bass technique).