Every season of Think of a Number ever, ranked from best to worst by thousands of votes from fans of the show. The best seasons of Think of a Number!

Johnny Ball, with the help of a studio audience, will show some mind-stretching models, blistering ballistics, lightning calculations and some shocking ways to store your energy - and let it go.

Episode 1

This week Johnny discovers why hands are so handy, how to make sense of your senses, automate an automaton and how bionic a bionic man can be. Meanwhile - Think of a Number - How many times can you take 3 from 24 ?

Episode 2

This week Johnny looks at family trees, works out how to get rid of a boomerang, puts nylon in an endless spin and turns a fossil back into a dinosaur with the aid of an element that never forgets. Meanwhile - Think of a Number - a half is a third of it - what's the number ?

Materials

Lots of giggles and quite a few gurgles as Johnny explores water from H to O. Meanwhile - Think of a Number. At a quick guess, which set of numbers has the larger total ?

Water

This week Johnny discovers some dicey things about dice and a number over a thousand miles long; also something heavy about gold and cutting about diamonds. Meanwhile - Think of a Number. By using two minus and one plus signs make this all add up! 123456789 = 10

The Shape of Wealth

This time Johnny considers why the Earth is in a flat spin; talks about what makes tocks tick and how to gain on the swings and roundabouts. So meanwhile - Think of a Number - Divide 50 by a half and add three. What's the answer ?

Episode 6

The cold facts about squeezing a lot into a little. See how a little hot air can make a lot go a long way, and before the end of the Programme some of the audience will get blown up! So, sit down and find out how, with a bit of inflation, you could be on the move. Meanwhile - Think of a Number - squeeze six marbles into a matchbox and divide them between three boys and three girls so that each person receives a marble but one marble remains in the box.

The Pressure's Mine

The people who thought nothing was something - the man who invented nothing. People who have managed to sell us nothing. How can you measure nothing ? And how the force of nothing keeps things up and holds us together. So if you have nothing on, except BBC1, discover that there's more to nothing than meets the eye. Meanwhile - Think of a Number - Quickly multiply this... it takes no time at all. 1x5x8x3x4x0x9x6x7x2

Absolutely Nothing

Faces - old faces, new faces. Pulling faces and painting faces. Discovering that looks are more than skin-deep. See the woman who has at least 60 faces and find out how a face can get you anywhere. So prepare to face the fact that you may not be able to face yourself in quite the same way again. Meanwhile - Think of a Number: two faces - father and son - when the father was 31, the son was eight. Now the father is twice as old as the son. How old is the son now ?

Face Facts

Reflect on the speed of light and the colour of space. Why Father Christmas is never seen. See what your screen looks like in black and white, red, blue and green. A solar plane that could reach new heights and how you could ride on a sun-beam for free... So if you don't want to be in the dark switch on to see the light - from infra red to ultra violet. Meanwhile - Think of a Number - it's all relative! If 2 is company and 3 is a crowd, what are 4 and 5?

Seeing the Light

Computers - digital computers, electrical computers, wind, steam and sun computers. Computers that talk and computers that draw. Plus an invitation to knock about the oldest computers known to man. Meanwhile - Think of a Number: spot this one without the aid of a computer! What arithmetical symbol can you or a computer use between 2 and 3 to make a number larger than 2 but less than 3 ?

Mechanical Minds

Seeing how the problem of Cleopatra's Needle was sewn up, how to pull your weight and someone else's besides. See a tailor-made jacket that weighs 25,000 tons, which turns out to be a bit of a drag, not to say boring. So, mechanically speaking, it could be to your advantage to watch; even a moving experience.

Meanwhile - Think of a Number - get a move on with this! Make eight 8s and a few plusses move about to make a 1 and 3 zeros.

Getting Things Moving

The first of six programmes with Johnny Ball. Round wheels, not-so-round wheels, oval wheels, big wheels, little wheels; and a chance to see how you can go backwards while going forwards! Plus an eccentric bike and the newest engine that goes straight round the world. Meanwhile, see if you can get around to solving this one. Cut up a circle into 22 parts using only six straight lines.

Wheels Within Wheels

He cooks, looks, hits, breaks and bends... glass. See some glass over 3,000 years old, a teardrop that goes with a bang and a singer who has a smashing time. Meanwhile, see if you can see through this one. Divide a clock face with two straight lines so that the numbers in each part are equal.

The Science of See-through Sand

Squeezing muscles, waving muscles, levering muscles, springing muscles and jumping muscles. He'll be in deep water seeing how Archimedes showed his muscles, how to travel first class and still keep a balance and how to keep a camera steady when you're all over the place. Meanwhile, flex your brain on this one: A round-the-world cyclist has travelled 15,951 kilometres. How many kilometres must he travel before his speedometer again shows a number which reads the same backwards ?

No Cockles, Just Muscles, Alive Alive Oh

Atomic elements, lit up elements, man-made elements and elements that melt in your hand. See how two people become the salt of the earth, the spoon that won't stir your cocoa and a machine that knows its place - underground. Meanwhile, try to iron out this one - hope it's not too 'Boron'. Three matches make four - how ? You mustn't break them.

Elementarianisticalizationableism... or it's elemental when it's on the table

Listening to loud sounds, soft sounds, old sounds and new sounds. Recording some of the first sounds. Investigating drums in the head. Transmitting sounds with a milk bottle and asking a machine to do the talking. Meanwhile sort this out 'ear: A record costs £2 plus half its price. How much does it cost ?

Hello Listeners

Doubling dimension, flexing flexagons and perceiving perspective. See the impossible triangle, two dimensional people who live in flats and the latest development in photography that is far from flat. Meanwhile weigh this up: If you put three quarters of a cake on one side of a scale and half of a cake and a 250 gram weight on the other, it balances. What does the whole cake weigh ?

2D or not 2D, That is the Question

The first of six programmes with Johnny Ball This week Johnny finds out about reproduction, discovering where your heart is and what your voice looks like. Also a machine that looks like us, but doesn't think like us and next generation robots that don't look like us, but think like us. Meanwhile - get around to generating an answer to this one - how many grooves are there on the average long-playing record ?

Reproduction

Johnny finds out how to measure a metre, what keeps a marching soldier in line when he puts his best foot forward and how a laser gets the measure when spying on a locked room. Meanwhile - how many times can you take accurately three from 333 ?

What does exactly mean exactly ?

This week Johnny looks at a few musical numbers - discovering that time can change the National Anthem but still rule the waves. He also finds the key to play a violin, with no strings attached - what a fiddle!

Musical Numbers

Johnny discovers the secrets of Doctor Who's Tardis, a box that looks like one but isn't and a machine that makes boxes quicker than you can. Also there's a disappearing box, a multiplying box and a box that's bigger on the inside than it is on the outside. Meanwhile - box clever with this. Five balls in a box -can you give them all to five friends so one remains in the box ?

Box Clever

Find out how you can draw hyperbolas, parabolas and about the illusion that something is there when it isn't. So this week watch out for things that go with a swing, and for curves there's no place like cone.

Dangerous Curves

Find out if a fruit machine is fair and how skittles are at the fair. Also see some of the latest electronic games including some that talk backl Meanwhile, see if you're game for this one: line up ten balls in a box so that there are an equal number along each side.

Gambling

A 6 part series with Johnny Ball. Johnny bounces back with some lighthearted explorations into numbers and science. This week Johnny gets thrown off balance by two junior judo champions, but realising the gravity of the situation, recovers sufficiently to take a bicycle ride on a tightrope. Does he fall off ? Weight and see! Meanwhile - weigh this one up. A half is a third of it... what is it ?

In the Balance

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

Bounce and Stretch

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.

Planes and Flights of Fancy

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.

The Maze of Ways from A to B

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.

Say it with Numbers

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!

Beat It!

A light-hearted exploration of maths and science, presented by Johnny Ball.

The Best Seasons of Think of a Number

The Best Seasons of Think of a Number

Season 1

Season 2

Season 3

Season 4

Season 5