# M4.4.8

**scale drawings**can help one measure distances and angles that are inconvenient to measure directly.

### How Big Is the Earth?

In collaboration with another school north or south of yours, rnuse the method of Eratoshenes to determine the circumference rnof the Earth.

### Estimating Planar Areas Using Analogue Methods

A method to estimate planar areas for simple or complex shapes is described. The method relies on the use of weighing the area of interest and using proportional constructs.

### Learning from Slide Rules

In the days before calculators and personal computers an engineer always had a slide rule nearby. These days it is difficult to locate a slide rule outside of a museum.

I don't know how many of those who have used a slide rule ever thought of it as an analog computer, but that is really what it is. As such, the slide rule can be used to teach the modern view of the relationship between nature and mathematics and about the formalization of this concept known as isomorphism, which is one of the most pervasive and important concepts in mathematics.