Applied Science - Science and Math (2B)
Lab 

   
OBJECTIVES:
  • Recognizing and comparing shapes.
  • Modeling different shapes.
VOCABULARY:
  • depth 
  • shape
  • three dimensional
  • two dimensional
MATERIALS:

Students make three dimensional objects from cookie cutters.

BACKGROUND:

Shapes are all around us.  Some shapes are used to identify, such as traffic signs.  Many people take shapes for granted, not realizing  the historical significance that many have.  Students should be familiar with a deck of cards. Show them a deck of cards.  Ask them what shapes are represented by American playing cards.  Hopefully they will tell you spade, heart, diamond, and clubs.  Ask them if they know where these symbols came from.  Do they think it was a 3 dimensional object or a 2 dimensional object?  (Actually these terms refer to both the 3d and 2d version).

These shapes have a historical development.  The English liked the French symbols and came up with names to describe them.  The original shapes are from heart = biological heart; diamond = mineral; and spade = a tool that farmers used.  The club is more difficult to explain; and this is probably why it is the hardest shape to "remember".  The club came from the English version of a "trefle" or three foil from the French.  The English card-makers thought it looked like a "club."

Children can  have difficulty visualizing the original three-dimensional shape after it has been made into a  2 dimensional one .  Cookie cutters are a great example.  Children sometimes believe that by making cookie dough thick and then cutting their shape out, they are creating a 3 dimensional shape.  They often forget the features which were compressed in order to make it 2 dimensions, like a nose, mouth, or muscles!

PROCEDURE:

Emphasize that shapes are all around us.  Some we can model easily, but others are difficult.  Tell students many people, even teachers, use 2 dimensional items for something that is 3-dimensional.  Students will have to think before they name a shape.  The difference between 2 dimensional and 3 dimensional is that 3d has depth or as it is commonly referred to, the "third dimension.”  The other two are length and width.

  1. Instruct students they will be turning a cook cutter shape into a 3 dimensional object.  Make sure clues are give on how to turn a 2 dimensional cookie into a 3 dimensional object.  However, do not show them an example, because the key is for the children to discover for themselves how “flat” or two dimensional they really see the world.
      
  2. Give students a piece of wax paper to do their activity on.  Provide enough clay or play dough so they can roll it out as “dough.”  If you have rolling pins you may want the students to roll it out.  You can prevent a mess by first putting another piece of wax paper over the clay and then rolling it.  If you don’t have rolling pins the students can flatten the clay by pounding on it with their hands.
      
  3. Each person in the group should make a cookie cutter shape.  Direct them to construct a three dimensional model of the cookie cutter shape.  For instance, a circle should turn into a sphere, but you can also consider a cylinder correct.  If you have a “gingerbread” type cutter, students should include a nose, mouth and other three dimensional characteristics of a person.  Again children can have a difficult time understanding three-dimensional objects..  They believe that thickness is enough.  Guide them to understand this concept and they will remember it their entire life.

  RECIPE FOR PLAY DOUGH  
  MATERIALS:

   250 ml flour
   125 ml salt
   5 ml cream of tartar
   250 ml water
   about 1 ml food coloring
   about 1 ml oil
 

DIRECTIONS:

Cook, with stirring, over medium heat until the gloppy mess looks like play dough.  Knead briefly after the mixture has cooled a little.  You will need to multiply this recipe by 6 to get enough for a class of 30 students, but it should be made in two batches.  Large amounts of dough are difficult to stir because the mixture becomes firm.  Store the play dough in a plastic bag or margarine tub.

Play dough can be made and saved for a long time if it doesn't dry out.  Color the various play dough mixtures depending on the activity.  Many activities do not require a specific color. 

 [Dictionary]
  [Back to Applied Science Grid]  [Back to Science & Math (2)]