Shape Hunt Slides
The Imposter
Shape Hunt
Classified: 2nd Grade Geometry
Warm-up
Stand Up Sit Down
Stand Up!
If the parts are Equal
Sit Down!
If the parts are Unequal
"Get ready for the shape reveal..."
Evidence Collection
Watch & Detect
Embedded media
Look closely for "Imposter" shapes that aren't divided fairly!
Pause Point 1
The Pizza Test
"If this was a pizza, which one would you want to share with 3 friends?"
Which looks "fair"? Why?
Alert
Spot the Imposter
Look at the squares on the screen...
Which square has 4 parts but isn't fourths?
Explain WHY it's an imposter!
Detective Files
Case Vocabulary
Equal Sections
Parts that are the exact same size or area. They are "fair."
Thirds
A shape divided into exactly three equal parts.
Fourths
A shape divided into exactly four equal parts.
Imposter
Parts that are not the same size, or the wrong number of parts!
Mission
The Shape Sort
1
Get your Sorting Deck and Evidence Mats.
2
Work with a partner to inspect each card.
3
Place cards in the correct pile: Thirds, Fourths, or Imposters.
Extension Challenge
Pick one Imposter and draw the "Corrected Evidence" on the back!
Case Briefing Teacher Guide
Case Briefing
Teacher Guide
Lesson Objective
Students will distinguish between equal and unequal parts in various geometric shapes (circles, squares, rectangles) to accurately identify representations of thirds and fourths.
Grade Level
2nd Grade
Duration
45 Minutes
Material Evidence
- Shape Hunt Slide Deck
- Detective Activity Pack
- Sorting Mats (per pair)
- Shape Cards (per pair)
Interrogation (Discussion) Guide
0:01 - The Pizza Test
"If this was a pizza, which one would you want to share? Why?"
Goal: Prime intuition about fairness and equal area.
0:55 - Spot the Imposter Square
"There's a square with 4 parts that ISN'T fourths. Which one? How do we know?"
Goal: Distinguish between counting parts vs. measuring area.
2:34 - The Final Challenge
"Name the fractions for all four rectangles before the narrator tells us."
Goal: Review Halves, Fourths, and Sixths.
Mission Log (Procedure)
01
Warm-up: Stand Up, Sit Down (5 min)
Use the slide deck to show various shapes. Students stand for "Equal" and sit for "Unequal." This builds quick visual recognition of fair shares.
02
Case Briefing: Video Viewing (10 min)
Watch the Khan Academy video. Use the pause points to engage students. Have students identify "distractor" answers and articulate why they are incorrect (e.g., "too many parts," "wrong sizes").
03
Field Work: The Shape Sort (15 min)
Students work in pairs. They sort the card deck into three categories: Equal Thirds, Equal Fourths, and Imposters. Circulate to check for students who are only counting parts without checking size.
04
Lab Work: Correction (5 min)
Students select one Imposter card. On the back, they draw a "corrected" version of that shape that shows either equal thirds or fourths.
Common Misconceptions
-
The Count Trap:
Students may think any shape with 4 parts is "fourths." Remind them: "It has to be four equal parts."
-
The Lines Trap:
Students might think parallel lines always create equal parts in a circle. Use the "Pizza Test" to show that the outer "crust" pieces are smaller.
Detective Activity Pack
Detective Activity Pack
The Imposter Shape Hunt
ID: ________
DATE: ________
Mission Instructions
- Cut out the Shape Cards on the next page.
- Place the Sorting Mats on your desk.
- Work with your partner to inspect each shape. Is it fair? Are the parts equal?
- Sort them into the correct pile. Piles: Equal Thirds, Equal Fourths, or Imposters.
Lab Work: Correct the Evidence
Pick one Imposter card from your pile. Draw it correctly in the box below to make it "fair."
The Imposter (Copy what it looked like)
Corrected Evidence (Make it Equal!)
This shape is now divided into:
Thirds
Fourths
Detective Sorting Mats
Equal Thirds
Place Cards Here
Equal Fourths
Place Cards Here
Imposters
Place Evidence Here
Shape Card Deck
Cut along the dotted lines
