ACTIVITY 14, Breakdown, Introduction, Part A & Part B planning

After reading the introduction to the activity and filling in a 3-square, we had a discussion about surface area.  I demonstrated the effect of breaking an object in pieces on its surface area.

The first demonstration uses Cuisinaire rods.  Look at the photos below.  Count each square side of each piece of the 3-cube object.  Include in your count sides that are hollow and sides that have an extra "piece" on the end.

In this first photo there are 14 squares:

In the second photo there are 16 squares, 10 on the 2-cube piece & 6 on the 1-cube piece:

In the last photo of cubes, there are 18 squares, 6 per cube.

The area of the outside of an object is called the surface area of the object.  The idea of this demonstration is to show you that the number of pieces you break an object into affects the object's surface area.

Now, let's look at photos of pieces of antacid tablet.  You'll work with antacid tablets in this Activity, #14.

Here's a whole antacid tablet together with a drawing of the pieces that make up its surface area:

 You can see that there are two circular pieces and one long skinny strip.  The skinny strip shows the edge of the tablet when it is "unrolled" away from the tablet.

Here is a tablet broken in half, together with a drawing of its pieces:

Now it looks as if there is more surface area to this broken tablet than there is with the whole one.  There are two more edge pieces than the whole tablet had.

This last photo shows an antacid tablet broken in 4 pieces, together with a drawing of its pieces:

Notice now that there is even more surface area than the tablet that was broken in half.  I hope you are beginning to see the pattern in the relationship between the number of pieces of the tablet and the amount of surface area it has.