Shape Maker Slides
Flat VS Fat
The Mystery of the 3D Pyramid
Shape Maker 17 1/2 Factory
Warm-Up Challenge
The Paper
How would you describe this shape?
The Book
How is this different from the paper?
Shape Maker 17 1/2
Watch: 6:45 - END
Embedded media
What was that last shape that entered the machine?
Shape or Object?
"Flat" Shapes
They are 2D.
They are flat like a pancake.
"Solid" Objects
They are 3D.
They have height and depth!
Flat vs. Fat Sort
01
Explore
Look at the items on your table. Touch them! Hold them!
02
Sort
Is it a "Flat Shape" or a "Solid Object"? Put it in the right bin!
03
Explain
Tell your partner WHY it belongs there. Does it have "fat" on it?
?
Mystery Bag!
"I feel something... it has points. It has flat sides. It feels like a block!"
Can you guess the object before we pull it out?
Flat and Fat Teacher Guide
Flat and Fat Shapes
Teacher Facilitation Guide
Grades 1-2
Lesson Objective
Students will distinguish between 2-dimensional (flat) shapes and 3-dimensional (solid) objects. By observing attributes like height and depth, students will categorize items into "Flat" or "Fat" groups.
Materials Needed
- 2D Paper Shapes (Cutouts)
- 3D Objects (Blocks, Dice, Balls)
- Opaque "Mystery" Bag
- 2 Sorting Bins / Mat
- "Shape Maker" Slide Deck
5 MIN
1. Warm-Up: The Comparison
Demonstration:
Hold up a single sheet of paper (Rectangle) and a thick book (Rectangular Prism).
"Class, both of these have four corners. They both look like rectangles. But if I try to stand the paper up, it falls over. If I stand the book up, it stays. Why?"
Key Insight
Guide students to notice that the book has "thickness" or "fatness" (depth/height), while the paper is "flat."
10 MIN
2. Viewing & Logic
Watch Shapes! | Mini Math Movies (Start at 6:45).
Discussion Prompt:
"The narrator says the pyramid is an object, not just a shape. What does he mean by 'object'?"
Vocabulary Check:
Introduce 2D (Flat) and 3D (Solid). Use the mnemonic: 2D is like a drawing; 3D is like a toy.
20 MIN
3. Flat vs. Fat Sort
Divide students into small groups. Provide a bin mixed with paper cutouts and physical objects.
- Step 1: Students pick one item and decide if it is "Flat" or "Solid."
- Step 2: They place it in the designated bin (use "Bin Labels" material).
- Step 3: Partners must explain why. "I put the ball in 'Solid' because it doesn't lay flat on the table."
10 MIN
4. Closure: Mystery Bag
How to Play:
Place a 3D object (cone, sphere, cube) in the opaque bag. A student reaches in (no peeking!) and describes the attributes: "It feels round... it has no flat sides... it can roll." The class guesses the object. Ask: "Is it a flat shape or a solid object?"
Shape Sorter Recording Sheet
Shape Sorter
Name:
Date:
How to Sort
Look at your items. Is it FLAT like a pancake? Or is it FAT like a toy? Draw 3 things you found in each box!
Flat Shapes
2-Dimensional (2D)
Item 1
Item 2
Item 3
Solid Objects
3-Dimensional (3D)
Item 1
Item 2
Item 3
Mystery Question:
Pick one Solid Object. How is it different from a Flat Shape?
