Watch Johnny spring through sand, cement and sponge cakes and discover new angles to pool playing.

This week Johnny Ball airs his views on Plain Planes and Flights of Fancy with the aid of paper darts, boomerangs, kites and the only model jet aircraft in the world.

Johnny takes off his waistcoat without removing his jacket and spins his way through maps and mazes, helped by a robot mouse. So if you're knot amused, at least you'll be amazed.

Johnny whistles for the thistle sifter, finds out how a turtle draws and even meets a computer that talks back. So, in a few words - sag a teat in front of the belly.

This week, the last of the series, it's Think of a Number and Beat it! Johnny discovers that hitting things together goes down with a bang, crash, wobble and bonk - as well as a laugh. So if the mood strikes you-hit that button and watch out!