Elementary Mathematics-Science SMILE Meeting
20 March 2001
Notes Prepared by Porter Johnson


Section A: [K-5]

Barbara Hill (Fernwood School 1-5 Special Education) Handout:  Geometry in Pictures, Pillows, and Places
placed transparent sheets with images of two dimensional [rectangle, triangle, square, circle], as well as some three dimensional geometrical objects [tetrahedron, cone, cube, sphere, prism, and cylinder] on the table.  In addition she gave us a big sheet of cardboard stock [about 20 cm ´ 50 cm] and a plastic metric ruler. Then we began to work on her 5 week lesson plan on Pictures, Pillows, and Places.

We posed for Barbara for our group photograph, but unfortunately there was no film in her camera! What a shame!

Joyce McCoy (Spencer School Head Start 3-5 year olds) Preparation of a Windsock
put the following ingredients on the table: 

We came up to the table and made our own Windsocks. Very good, Joyce.  For additional information see the websites, A Variety of Ways to Make a Windsock, http://www.track0.com/canteach/elementary/earthspace16.html and Wind: http://eduscapes.com/42explore/wind.htm.

Cynthia Southern (Spencer School Kindergarten)
Handout: Where's the Mathematics?
(The Super Source, Cuisinaire 1996). She had us make planar geometric figures using rubber bands on a square lattice with a 5 ´ 5 array of smooth plastic "nails" sticking through it.  The device, called a Geoboard, can be used to make triangles, rectangles, and squares of various sizes and shapes, to illustrate concepts of geometry at an elementary, constructive level. Students construct the figures, cut out paper models the same size and shape as the figures, and consider questions like these

At first students are apt to make figures with the sides parallel to those of the Geoboard, but they will learn to make other shapes. Very good, Cynthia! For additional ideas concerning Manipulative Mathematics, see the website http://nlvm.usu.edu/en/nav/vlibrary.html.

Notes taken by Earl Zwicker

Section B: [4-8]

Earnest Garrison (Jones Academic Magnet HS)  Electromagnetism
He showed how to unify the presenting of the topics of Electricity and Magnetism using phenomenological exercises, rather than following the traditional approach of separating these topics:

Earnest led a discussion about the difference in a big battery and a small battery. He asked whether the bulb burns brighter with a big battery than with a small one. We decided that the Voltage produced by the battery determined how brightly the bulb would burn, whereas the size of the battery might determine its capacity, and thus determine how long the light would burn before the battery was discharged.

Porter Johnson asked what was the difference between these standard types of 1.5 Volt batteries:

In particular [1]What's inside these batteries? and [2] How come they all produce the same voltage? He explained that inside a 1.5 Volt (Leclanche) dry cell battery there is a Zinc anode, a Manganese Dioxide cathode, and an aqueous ammonium or zinc chloride electrolyte that is "gelled" by addition of an inert metal oxide.  Details are described at the URL http://www.powerstream.com/BatteryFAQ.html#lec. The same voltage is produced in all dry cell batteries because they all are driven by the same chemical reactions. These reactions are complicated, but for full discharge of the battery can be considered approximately to be the following:
Zn + MnO2 +2 H2O + ZnCl2 Û 2 MnOOH + 2 Zn(OH)Cl
A 6 Volt dry cell battery contains four independent 1.5 Volt dry cell batteries that are hooked in series. [For comparison, the basic 12 Volt automobile battery actually contains 6 independent lead-sulfuric acid wet cells hooked in series, each producing about 2 Volts.]  Here are some additional sources of information about batteries:

Valvasti Williams Jr (Bass School)  How do you make a motor or generator?
Val began by reciting the familiar mantra of Zoris Soderberg [Clark School]; namely, the K-Method for Effective Teaching:

He took a dry cell battery, two paper clips, two wire leads, a wooden dowel rod [cylindrical, with diameter » 1 cm and length » 10 cm], a rubber band, a small permanent magnet, a small Styrofoam™ board, and a 1 -2 meter length of fairly stiff copper wire with plastic insulated coating.  We wound the wire around the dowel to form a circular coil of » 20 turns.  We suspended the wire coil over the magnet so that it rotated freely about the axis formed by its straightened ends, using the paper clips.  The plastic coating was scraped from one side of the wire, so that, as the wire loop rotated it alternately made and broke electrical contact with the paper clips.  The paper clips were attached to the battery electrodes using the two wire leads and rubber bands.  The system looked like this:

Source: http://www.hometrainingtools.com/build-motor-project/a/1605/
The purpose of the half-stripped wire was for the current in the wire to be shut alternately on and off as the loop rotated, serving as a commutator.  We made a very nice electric motor using this technique, and were able to get the get the motor running continuously after a little practice.  Just as an electric motor [such as the starter motor in an automobile] converts electrical energy into mechanical energy, an electric generator [such as an automobile generator or alternator] converts mechanical energy into electrical energy.    

Notes taken by Porter Johnson