1. Inventing benchmark, the measuring tool was first invented at the beginning of the area. Is it a triangle? Round? Or a square? People finally chose the square, because the square can be filled with rectangles or squares, and equilateral triangles and circles will always show a little.

2. Measurement, which is divided into two parts: translation and stretching. Let's start with translation. Take a rectangle for experiment, that is, its length can be placed on several benchmarks, and its width can be placed on several lines, all on one benchmark. The extent of stretching is also different. How many times has the length of the rubber band been stretched? See how many times the width has been stretched. This is stretching

3. unify the unit. One day, Xiaoming and Xiaohong stood in the same square. But the results they measured are actually different (,,? ,,)。 So we should unify the units, one square centimeter (cm2), one square decimeter (cm2), one square meter (m2) and one square kilometer (km2). ...

4. Measuring space, many people are puzzled why a small two should be written on the abbreviation of English square. That's because a square is a two-dimensional space. Many people wonder, what is two-dimensional space? Let's talk about measuring space first. First of all, from the simplest one-dimensional space, it is a line. Two-dimensional space, that is, a surface we just talked about. Three dimensions are normal bodies. What about four dimensions? Haha, no one knows what four dimensions are! Or someone wants to ask, what about zero-dimensional space? Haha, no one knows (⊙? ) But we can make a bold guess! Could four dimensions be time? Maybe in four-dimensional space, the outside is big, the inside is small or vice versa. Can the small zero-dimensional space outside be thought about? Something you can't see. Then why? () Maybe he really exists (//? //)。 Who knows?