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Today’s Number
14
Look quick and then draw!
• What did you notice about
the shape?
• Describe it!
• Number of sides?
• What about the angles?
Look quick and then draw it!
• What did you notice about it?
• Describe it!
• Number of sides?
• What about the angles?
Draw it!
Think Time!
• What did you notice the first time you saw
the shape?
• Could you remember the whole shape?
• What happened when you saw the shape the
second time?
• Did that help you add anything or change
anything?
What do you know about these?
Diamond
4 sides
Right Angle
3 sides
Hexagon
Octagon
6 sides
8 sides
What was similar about them?
• Straight lines
• They all have corners or angles.
• They are all closed.
• They do not have openings.
Polygons
• All the shapes we have been looking at are
closed shapes with straight sides.
• They have corners or angles.
• Mathematicians have a name for these types
of shapes.
• The are called polygons.
• Polygon means “a shape with many sides.”
We will be working on geometry for
a few weeks.
What is geometry?
Do you know what we might be doing?
What kinds of materials do you think we
might use?
This is a rectangle. I am holding a
prism. How are they different?
Two-dimensional shapes
Three-dimensional shapes
• Sometimes we will be working with flat
shapes like the rectangle. They are called
two-dimensional shapes.
• Other times we will be using solid objects
like the Geoblocks. They are called threedimensional shapes.
Helpers Pass out the Geoblocks!
Look at one block. Let’s describe it
and record what we notice.
Describing Geoblocks
Made of wood
Cube
Pyramid
smooth
Face
• When mathematicians talk about a three
dimensional object, such as a Geoblock, they
call the side of the block a face. When you put
your block down on the table, it sits on one of
it’s faces.
What do you notice about a face of your
Geoblock?
When you touch it with the palm of your hand,
what does it feel like?
Describing Geoblocks
Made of wood
cube
pyramid
smooth
flat
Geoblocks
• The shapes are either triangles or rectangles.
• They either have five or six faces.
• We will think a lot about the shapes of the
faces of Geoblocks and the number of faces
that the different Geoblocks have.
Your Turn!
• Count the faces on your block.
• How many faces does it have?
• Let’s record the different numbers.
• Now let’s sort the blocks by the number of faces.
Sorting by Faces
Stand up if your Geoblock has 5 faces.
Stand up if your Geoblock has six faces.
Compare the Shapes
Those of you who are holding shapes with six
faces probably noticed that the faces of your
blocks are squares or rectangles. These
blocks are called rectangular prisms.
Raise your block in the air if you have a
rectangular prism with only square faces?
Do you know the special name for it?
Cube
• A cube is a special kind of rectangular
prism.
• All of its faces are squares. If you have a
cube, hold it up so that everyone can see it
again.
Let’s Draw
• We are going to try to draw our shape so
that it doesn’t look flat.
• We are going to make it look 3-D shape.
• Let’s see if you can draw it in a way that
helps us see more than just one face.
• We will look at some of the pictures and see
whether we get some ideas about how to
make our drawings look more realistic.
3-D Shapes
• Let’s look at some
3-D shapes.
Let’s draw some
ourselves.