Title
Introduction to Geometry
2Dimensional and 3Dimensional Shapes
(cube, sphere, rectangular prism, pyramid)
Rose Cavaliere: Internship I – Observed Lesson 2
Materials
·
whiteboard and markers
·
class list w/ assessment objectives to record results
·
pop up cube (starts flat, then pops open)
·
Brown paper shopping bag w/ groceries in that are 3D shapes
·
Poster Board labeled “Shapes Museum” with one side labled 2D and one 3D; have
pics from magazines as examples to glue on
·
Models of items to illustrate 3D and sides, lines segments, vertices that
unfold flat to show sides (plastic 3D shapes are in classroom)
·
Toothpicks and marshmallows
·
Cards to hand to pairs assigned them 3D shapes to build with the marshmallows
and toothpicks
·
Worksheet to cutout and tape together 3D shapes, scissors, tape
·
Magazines, scissors, glue
·
Tessalation coloring sheet
·
Worksheet to assess w/ 3D shapes and 2D shapes
Timing Outline
10:3011:20: 50 minutes
10:3010:45: hook & discussion
15
10:4510:50: Shapes Museum
5
10:5011:10: Marshmallow Activity
20
11:1011:20: assessment worksheet
10
50 minutes
Description
This lesson will introduce children to the concept of 3D shapes through the
analysis of physical items as well as opportunities to build and create these
shapes themselves. 2D items were
discussed in a math lesson earlier this week and this lesson is intended to
build upon that to add to their schema about geometric shapes and jargon.
Rationale
Reason with shapes and their attributes.
Distinguish between defining attributes (e.g., triangles are closed and
threesided) versus nondefining attributes (e.g., color, orientation, overall
size); build and draw shapes to possess defining attributes.
Compose twodimensional shapes (rectangles, squares, trapezoids, triangles,
halfcircles, and quartercircles) or threedimensional shapes (cubes, right
rectangular prisms, right circular cones, and right circular cylinders)
Analysis of Prior Knowledge
This is the second of three lessons on basic geometry principles (Lesson 1 was
geometric shapes (2D); Lesson 3
will be about symmetry). I spoke with Mrs. Cortez who informed me that she has
introduced them to the shapes (2D and 3D) in a previous lesson but it has not
been extended since then. During
Lesson 1 almost all of these students knew the names of the basic 2D shapes
(triangle, circle, square, diamond, rectangle, oval).
We discussed attributes of shapes (size, sides, angles) but did not go
into comparing and contrasting 2D and 3D.
We discussed what dimension means and I could tell it was the first time
they were looking at shapes this analytically.
Objectives/Assessments
Objective 
Assessment 
have students understand difference between 2D and 3D shapes 
oral responses explaining 2D and 3D;
pointing out objects that are 2D and 3D when presented with 2 choices 
have students match correct name to correct shape (sphere, rectangular
prism, cube, pyramid) 
have students complete sheet where they color in the object I name;

have students count sides and corners of 3D objects 
have students count sides of 3D objects (two opportunities will exist
for this: during marshmallow activity or closing activity) 
have students explore 3D shapes in the real world 
oral discussion and items brought in for Shapes Museum 
Hook
Remind them that we discussed shapes and their names on Monday and Tuesday. Be
quick and brief—no discussion. Then
I will bring in a pop up cube that will start out flat, then open to illustrate
2D and 3D. While it is flat we will count sides and corners.
While cube is open we will count sides and corners.
Activities
·
Bring out a brown paper bag w/ groceries/household items packed in it.
Grocery items represent 3D shapes. Shapes discussed today will be:
sphere, rectangular prism, cube, cone, pyramid.
·
Establish “Shapes Museum” w/ these items. Invite them to bring in items from
home (or draw items or cut pictures out of newspapers or magazines) to add to
the museum.
·
Show them and pass around 3D shapes; count the sides, discuss lines, corners,
intersection of lines (vertices).
·
Unfold one of the above shapes (one of the boxes of cereal for example) and
count the sides and lines again.
·
Marshmallow shapes (2D and 3D): give the children baggies with toothpicks and
marshmallows. Send them off in
pairs w/ assigned shapes to make (see pairings below)—they need to make the 2D
and 3D version. Set timer for 10
minutes. At end of 10 minutes as
them to show the 2D and 3D version of shape (for ex. make a square—make
another square—turn this into a cube)
·
Early Finishers: Challenge activity cutout 3D shape and tape together OR look
for 2D and 3D items in magazine, OR tessalation coloring sheet.
Closure
Have children return to their desks to complete an assessment worksheet that
requires them to label shapes as either 2D or 3D.
Differentiation
·
Early Finisher activities have two levels of complexity, one much more
challenging, one more basic.
Challenging activity: cut out, fold and tape together 3D shapes.
Basic Activity 1: look
through magazines for 3D shapes to glue into Shapes Museum. Basic Activity 2:
tessalation coloring sheet .
Students like Meisner, Yosvany, Jocelyn may quickly get the marshmallow activity
and need something more challenging to engage them while the rest of the class
explores 3D shapes. Yosvany, while
bright, can become disruptive when he finishes well in advance of the class.
Students like Jonathan D., Harlan, Nancy, Cathleen may need something
they can more readily succeed at.
·
For the whole class assessment I will use a worksheet.
When I name a shape they mark whether it is 2D or 3D; then we have them
match the 2D shapes to the 3D shapes.
·
The marshmallow activity allows students who still need reinforcement of basic
2D shapes to continue exploring at that level.
Students this may be necessary for are Nancy, Omar, Harlan, Stephanie.
This should be permitted and the concept of 3D can be continually
reinforced with them in future lessons (if I had future lessons).
·
By pairing students, they can assist each other.
Stronger students are paired with students who may need more support.
3D shapes assigned during marshmallow activity will be by design based
on students in pairs. For example,
Yosvany, Pedro, Meisner, Jocelyn could probably handle a pyramid.
Some will get rectangular prisms, others cubes.
Instructions will include allowing some to make the 2D shape that starts
the 3D shape, then they help each other finish the 3D shape.
·
In general, I have tried to make this lesson as hands on and as visual as
possible, with a little seatwork and whiteboard discussion included as well.
For students like Yosvany and Hector the 3D marshmallow shapes will come
easily and will the cube cutout.
For students like Kathleen, Omar, Jonathan A. and Harlan, working with
strategies besides a worksheet will help them acquire this information. The most
basic activity, the coloring sheet, will allow students such as Kathleen to
participate and still work within the topic.
·
Very strategic pairing needs to occur with Hector (who is a behavior problem)
and the following students who, for every activity consistently exhibit delays:
Jonathan A., Nancy, Kathleen, Harlan, Vincent, Stephanie, Omar, Jonathan
A.
·
All pairs were selected w/ a stronger/needs support combination in mind (mixed
ability). During Marshmallow
activity one person makes the 3D and one person makes the 2D;
2D and 3D shapes are also assigned strategically.
·
Also, by making three groups with mixed ability pairs, groups are heterogenous.
Then, by making the lesson about 2D and 3D shapes I can assign the
students who need more support the task of making the 2D shapes.
Groups/Pairs
Groups are designed to pair a stronger performing student w/ ne who needs more
support either academically or behaviorally.
Student name on top is stronger student.
Kaylie
Stephanie 
Zahid
Nancy 
Jocelyn
Vincent 
Vilma
Jonathan A. 
Eric Chaj
Omar 
Ebenezer
Jennifer 
Hector
Kathleen 
Jonathan D.
Adrian 
Joel
Dennis 
Meisner
Harlan 
Eric Cuzco
Taylor 
Pedro
Yosvany 