Sir David Attenborough has turned geography teacher as millions of schoolchildren remain at home – saying he hopes they "feel inspired".
The broadcaster and naturalist said he was "delighted" with his temporary role.
A clip featuring the 94-year-old's unmistakable voice, from one of his virtual lessons, has been released.
"I am delighted to be teaching primary school children across the country about the things I am passionate about," he said of the lessons, which debut on Tuesday.
"I hope children will learn something new about animals, oceans and dinosaurs, and feel inspired by my BBC Bitesize lessons."
Five to seven-year-olds will be given a whistlestop tour of the continents and what makes them so unique, while seven to nine-year-olds will learn about the Equator.
Pupils aged nine to 11 will be taught the importance of maps in exploring surroundings.
The lessons feature animations as well as footage from the Natural History Unit but no shots of the broadcaster himself.
Sir David will tackle continents, the climate, maps, ocean migration, weather patterns and fish in his various lessons.
Later in the month, he will teach primary school pupils about dinosaurs and fossils as part BBC Bitesize Science Week.
Danny Dyer, Stephen Fry and Doctor Who star Jodie Whittaker have also signed up for the BBC's education efforts.
– Sir David's geography lessons will take place across BBC Bitesize Daily Primary, available on BBC iPlayer and Red Button.