Students create a mashup, hiding parts of their friend’s face within another image, and pose the question: What is the greatest fraction of a person’s face that can be revealed before figuring out who it is? What is the smallest fraction that can remain hidden so it is still recognizable? In comparing different mashups, students explore which fractional quantities are larger, smaller or equivalent.

*Comparing Fractional Quantities and Equivalent Fractions*

Expected Activity Time Hidden Face Challenge (20 minutes)

- Hidden Face Challenge Student Sheets
- iPad with Fraction Mash app
- Wifi access for sharing mashups

*Intro*: Do you ever see faces hidden in objects? In this activity, you will hide your face in an object in two ways: 1) trying to show as much of your face as possible yet still be hidden, and, 2) show as little of your face as possible yet your classmates can still tell it’s you in the picture.

*Hidden Face Challenge:* Create two images, one in which you are trying to show as much of your face without being recognizable to the class, and another where you are trying to show as little of your face as possible while still being recognizable.

What To Do

Hidden Face Challenge (20 minutes):

Have students open the app, and select “Make A Mashup.” To start, students need to choose two pictures to mash, one of an object and one of themselves.

- Students can import from the camera roll or take new pictures.
- Suggest that students turn on the Overlay feature while taking a new photo to help them line up their shot.
- To adjust individual photos in the frames, students can use two fingers to zoom or rotate. Encourage students to think about where they want to place the face on/in the object and:
- Decide whether they are trying to show as much of their face but still be hidden or as little of their face but still be recognizable.
- Experiment with choosing parts and selecting Combine to check to see how the mashups look.
- As they work, have students save their mashups.
- Once saved, anonymously post their images to the online project space or send them to you (the teacher) so you can share them with the class.
- Have students rate which ones show the greatest fractional parts of the whole to least for each challenge. Pick winners.

Prompt students to share the mashups they made and what they had to do to achieve the effects they wanted. Ask students:

- Which mashups have the fewest fractional parts of the whole? The most?
- What grids seem most effective in revealing or hiding someone?
- How do the pictures with unlike denominators compare?
- As you created your mashups, did you notice any parts of your face that was highly important to achieving the effect?

Examples of language and discourse to listen for as students engage with Fraction Mash:

- “The larger denominator gives me more pieces, but they’re smaller.”
- “The face sections are about the same as the object sections, yet the face still seems hidden because …”
- “1/2 is a larger piece than 1/9 so …”
- Statements about comparative fractional quantities and ways in which increasing or decreasing denominators helped to achieve the result they were after.

Examine what fraction of the whole image their different facial parts are. The faces can be resized by zooming. How does this affect the fractions of each part (eyes, nose, etc.)? Is the eye 1/8 of the face? 1/10? etc.