Put aside the "pie-charts" for the nonce. Kids can study RATIOS (fractions, decimals, percentages) to learn:

• Why no giants can exist on The Earth.
• Why the largest land animal ever was a brontosaurus who had to live in swamp water.
• Why our largest animals can only survive in the water.
• Why a mouse can fall ten stories and survive but climbs from water carrying his weight in water.
• Why RATIOS (fractions, decimals, percentages) show how our world is divided into separate REGIMES.
• How RATIOS lead us to G-Processes which explain how "the Universe" works.

In 1638, Galileo (1564-1642) published Two New Sciences. One "science" was that of kinematics, the STUDY OF MATTER IN MOTION WITHOUT REFERENCE TO FORCES, in particular, THE LAW OF FALLING BODIES (which was actually discovered in the 1240's by "The Merton Scholars" of Oxford University). The other "science" attempts to explain how "things grow". Galileo noted that WEIGHT depends upon VOLUME -- which is LENGTH CUBED, while STRENGTH depends on CROSS-SECTION OF MUSCLE, which is LENGTH SQUARED. Thus, if LENGTH DOUBLES, WEIGHTS INCREASES EIGHT-FOLD, WHILE STRENGTH ONLY INCREASES FOUR-FOLD. It's another matter of diminishing returns".

So, the GIANTS of fairy tales and legends CANNOT EXIST ON THIS EARTH. Even if you could conjure one up -- standing on his feet -- he would break his leg on the first step!

So a large animal needs the bouyancy of water to sustain it. Hence, the largest land animal we know of was a brontosaurus who had to depend upon swamp water to sustain it.

Hence, our largest animals -- whales -- can only exist in water -- the oceans.

I learned about the mouse from the British biologist, J. B. S. Haldane (1892-1964), in his fascinating essay, "On Being the Right Size". (You'll find this in V. III of The World of Mathematics, Edited by James R. Newman.)

Briefly, if a mouse were dropped from the 9th floor of a building, it would be stunned on landing, but able to walk away. A human falling from the 9th floor would be killed by smashing. And Haldane says that a dropped horse would "splash".

Why the difference? The mouse seems to demark a frontier in the gravitational domain. Why?

Because of a particular fraction: THE RATIO OF MASS (WEIGHT) TO SURFACE AREA. A body falling in an atmosphere encounters displacement of air as the body passes through the air. The amount of air the body displaces equals the surface area of the body. As length decreases for different bodies, the area decreases by the square of lengths, hence, faster than length itself.

For example, if the lengths decreases by the fraction 1/2, the area may decrease by the fraction 1/4. This means that a small body has a greater ratio of weight to surface area than a large body. So the resistance of the air for a small body is greater than that for a small body.

That mouse dropped from the 9th floor of a building reaches a certain terminal speed and drifts on down a few more feet to land. A human would have to fall a much greater distance to reach the point of "terminal drift".

And this means that GRAVITY IS NOT AS MUCH A PROBLEM FOR A MOUSE AS FOR A HUMAN.

On the other hand, this property works against the mouse in climbing from a pool of water. Haldane tells us that, due to surface tension, a mouse temporarily carries off on its body an amount of body equal to its own weight. Could you easily get out of a bathtub of swimming pool if you temporarily carried off on youw body a weight of water equal to you weight? Wow!

So SURFACE TENSION IS A SERIOUS PROBLEM FOR A MOUSE, BUT NOT FOR A HUMAN.

Haldane says that a fly, trying to get a drink of water, is in danger of temporarily carrying on its wings a weight of water many times its own weight! In fact, Haldane says that a fly trying to get a drink of water is in the same kind of danger that a human is who leans over a cliff to pick a wild flower.

FRACTIONS DEMARK DOMAINS. I CHALLENGE you to find some other instances of this involving different physical phenomena!