Measurement Level 1: Units and the SI System

How tall are you? How heavy is a bag of rice? How hot is it today? Every answer is a number and a unit, and this course is about those units: where they came from, why they matter, and how to move between them. It is for anyone, with no maths beyond multiplying by 10, 100 and 1,000. Short lessons start with why people measure at all and why measuring with your own foot causes trouble, then meet the metre, the kilogram, the litre, the second and the degree, learn the small trick that makes the metric system easy, feel how big a million really is, and end with the SI - the one system of units that nearly the whole world shares - and a spacecraft that was lost because two teams used different units. You need only a ruler, a kitchen scale, a bottle and your own hands and feet.