TOP Flaps 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
	Powers of ten: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 <> 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13

Suggestions to Teachers

This book can be used in various ways to stimulate students' initiative:

1. A group of children makes its own series of drawings, or if possible three-dimensional models, with dimensions of, say, 50 centimeters or more, starting from familiar surroundings. Certain objects are first drawn on the scale 1:10, together with part of the room in which they are situated. In the next drawing this room is shown with the school building around it on the scale of 1:100. Then, at 1:1,000, the school building is drawn with its surroundings, and so on: the town or county, the district, the state, the continent, the earth. By then the significance of scale will be sufficiently grasped, and the pictures in this book can be even more clearly understood.

2. A group of children can also make a collection of drawings, in some cases models, of comparable objects all of the some category, on the same scale. Examples: objects like automobiles, ships, buildings; living creatures like mammals, insects, bacteria, viruses. Also planets, moons, asteroids, stars, clusters and galaxies, and molecules, atoms, nuclei.

3. Comparative studies can be made of the proportions 1:100, 1:1,000, 1:10,000, for example, to show how large is the size of the atomic nucleus in relation to the atom itself.

4. A large blackboard drawing can be made with a square measuring 1.5 meters, and an illustration measuring 15 centimeters in the book can then be put in the center. In this way a stronger impression can be gotten of the meaning of the proportion 1:1,000, a "jump" which has to be made more than four times to reach the atomic nucleus from a life-size picture, and nearly nine times the other way to reach the limits of our universe.

A Note on the Scale of These Illustrations

The system of metric measurements, based on multiples of ten, is used throughout this book:

1,000 microns = 1 millimeter	Approximate equivalents are:
1O millimeters = 1 centimeter	1 centimeter = about 2/5 inch
100 centimeters = 1 meter	1 meter = about 1 yard
1,000 meters = 1 kilometer	1 kilometer = about 5/8 mile