If you are interested in productivity tools and want to support my work, enter your email and mark yourself at Most of us were taught maths the wrong way round. Someone writes a formula on the board, you copy it, you do 30 questions, you take the test, you forget it. Nobody ever tells you where the formula came from or what problem it was solving in the first place. So in this one I wanted to start from actual zero. No formulas handed to you. Just people looking at the world, asking normal questions, and slowly building the tools to answer them. How many animals came back? What do you write down when the storehouse is empty? What do you owe? How big is the Earth you're standing on? How far is the Moon? By the end, you'll have gone from dropping stones in a pile to measuring the Moon with a shadow and a triangle, and hopefully sine and cosine will stop looking like three formulas to memorize. This took me a long time to make, so if you got something out of it, a like genuinely helps more than you'd think. And tell me in the comments which part you want me to go deeper on, because the next ones are already being planned. CHAPTERS 0:00 Why you think you're bad at math 0:30 The questions that came before numbers 1:41 Math is measuring 2:57 How many? Stones, marks, and the first numbers 4:02 Arithmetic: four ways an amount can change 4:19 The problem of nothing 5:52 Why you can't divide by zero 6:58 Negative numbers: the amount you owe 7:54 Why a number needs a direction 8:25 One walk, two answers: the need for a fixed unit 10:17 What a metre really is 11:11 Measuring what you can't reach 11:43 What an angle is (and why 360) 13:00 An orange, two toothpicks, and a shadow 14:43 Tangent: turning a shadow into an angle 15:58 Eratosthenes measures the Earth 16:57 Geo-metry: measuring the Earth 17:22 The shape of the universe, and the shape of a protein 18:56 Change your perspective 20:21 Every kind of geometry 21:13 How far away is the Moon? Parallax 22:10 Shape and scale: the idea behind trigonometry 23:22 Opposite, adjacent, hypotenuse 23:52 Sine, cosine, tangent 24:34 Hipparchus and the eclipse of 129 BC 26:30 What trigonometry really is 26:48 Trigonometry everywhere in physics 28:09 How far we've come, and what's next In the next part we pick up right where this one leaves off. See you there.