Students will take photos where everyone in the photos all appear to be the same height. They’ll use the Calipers Tool to collect data and will create a graph of object height vs. object distance for everything in the photo.
Size Wise Activity 4: Everyone is Equal
Exploring Direct Proportional Relationships

Expected Activity Time
Part I: Everyone is Equal Activity (20 minutes)
Part 2: Data Exploration (20 minutes)
Materials and Prep
- Everyone is Equal Student Sheets
- 1 iPad with Size Wise for each group of 3-4
- Wifi access to send work to other iPads or to online project space
- Measuring tapes (optional)
- Prep 1: Make sure students have ample space to take pictures at different distances (hallways are good)
- Prep 2: Assign roles
Activity Prompt
Achieve equality!  In a photo, anyway.  Take a photo of the whole group, making everyone  look like they are the same height in the picture. Stand up straight, everyone!
To Do
Have students stand up straight with two or more friends so that they all appear the same height in the camera view. Â Students should:
- Choose three or more people who are not the same height.
- Add a couple of other objects to the photo, like a chair, a backpack, a pencil, or a cup, placing them so that their image height is the same, too. To make it easier to line up all subjects, try taking the photo from low down at ground level.
- Measure each person and object with the calipers.
- Go to the Gallery and select the Data Tool.
- Compare the image sizes, actual heights and distances they see associated with each person. Â What patterns do they notice? Â Have them describe what they see.
- Using their data, have students draw a diagram of where people were standing in the shot and label their distances. Â Discuss what relationships they see between distance, image sizes, and actual heights of people. Encourage them to use ratio language to describe the relationships they see.
- Plot the data from one photo on a graph of object height vs. object distance. Â What do they see?
Discussion
Prompt students to make observations and encourage students to use ratio language and reasoning while completing the challenge.
- How is the height of an object related to the distance it had to be away from the camera?
- Is there a mathematical way to represent this relationship?
Language and discourse to listen for:
- Bigger objects need to be farther away to be the same size.
- To change an object’s image size, you have to change its distance from the camera.
Extensions and Inquiring Further
If image height is standardized across photos (e.g. all are an equal image size), they can plot the whole class’ data on one graph and discover direct proportional relationship between object height and distance.  Another fun way to standardize the image height is to choose a virtual prop from the virtual prop library to put in the photo.
Have students research the heights of other people and objects.  Once students have uncovered the directly proportional relationship between object height and object distance, they can use that proportional relationship to calculate the positions these objects should stand in order to make their image size “fit” in with the virtual prop (see Strike A Pose activity).
Part 1: Everyone is Equal
To Do:
- Create a Caliper for each person in your group.
- Arrange a group of three or more differently sized people so they appear to be the same height on screen. Â To do this, you will need to adjust their distances from the camera.
- Snap a picture of your group shot.
- Go to Gallery and tap the Data Tool. Â Note the data for each person and record in the table below.
Group Member |
Actual Height |
Image Size |
Distance from Camera |
Ratio:Actual HeightDistance from Camera |
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Do you notice patterns in the data? Please describe.
Part 2: Data Exploration

To Do:
- Create a diagram.
- Label the diagram with your group members’ actual heights and the distances they stood from the camera.
What do you notice about the actual heights of your group members versus their distances from the camera?

In Camera Mode, you will use: |
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To enter and calibrate the height of individuals, objects, and group members. |
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To reflect on the things they notice about the pictures they take. |
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 To see how image sizes of subjects relate to one another. |
In Gallery Mode, you can use: |
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To compare data across 4 pics (e.g., distances one has to stand to get different image sizes). |
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Write ratios seen in the photos they took. |