Bitmap Bookmarks
In this activity, students will explore how monochrome photographic images are stored on a computer.
This workshop consists of two parts: a PowerPoint presentation followed by a fun, interactive hands-on activity. Students will create a beaded bookmarks to be introduced to binary and Boolean values to demonstrate how computers store monochrome raster images.
What You Need
Physical Requirements
- A large classroom with a demonstration area at the front.
- Access to a computer and projector for the presentation.
Materials
- Blue pipe cleaner (1)
- Green pipe cleaner, halved (5)
- White beads (16)
- Black beads (9)
- Paper plates (optional)
- Pencil
- Scissor
Guide:
Presentation:
Worksheets:
Safety Notes
Ensure you are familiar with Let's Talk Science's precautions with respect to safe virtual outreach to youth.
What To Do
Pre-Activity Prep
- Create "bookmark kits" for each student consisting of 16 black beads, 9 white beads, 5 green pipe cleaners (halved) and one blue pipe cleaner stored in individual plastic bags or on a plate (optional).
- Print "Bitmap Bookmark Worksheet" for every student.
- Create a demo craft to show the students, through various stages of completion.
- Reserve one blue pipe cleaner and 5 green pipe cleaner halves so you can demonstrate how to start the craft.
Introduction (via Presentation)
- Discuss how photographic images are stored in a computer.
- Explain pixels and how a computer processes this information (machine language).
- Discuss Boolean values ("false" and "true" values).
Activity: Creating a Bookmark
- Once each student has received a worksheet, encourage them to translate the binary values in the table to Boolean values.
- Once students are done, they can pick up one long blue pipe cleaner and five halved green pipe cleaners (or hand out "bookmark kits").
- Using the pipe cleaners you reserved, demonstrate how to create a hook on the tip of the green pipe cleaner to attach the green pipe cleaners lengthwise onto the horizontal blue pipe cleaner.
- Students will use the chart on their worksheet to figure out the ordering of beads for each green pipe cleaner. Demonstrate how to do the first column.
- Have the students place the beads over the hook to secure it in place.
- As students finish their columns, demonstrate how to snip the green pipe cleaners with a scissor so they are not as long.
- Students will create another hook at the end of the pipe cleaner, threading it into the last bead of each column. This will make a loop.
- Lastly, they will bend one side of the blue pipe cleaner and thread it through the green pipe cleaner loop. They will secure it to the other end of the blue pipe cleaner.
Wrap-up
- Allow students time to ask any questions.
- Give the educator a blank encoding worksheet for future learning.
- Discuss possible careers related to the topics discussed in today's workshop and what is required (education, experience, etc.) to get into those careers.
Discovery
Photographic images can be stored in a computer either in lines and shapes (vector images) or in pixels. Pixels are known as "picture elements" and arranged in a 2-dimensional array, in a format that computers understand. Computers understand information through "machine language" or "binary". In machine language, data is represented as 0s and 1s, known as bits. When a computer receives information, it must be translated into 0s and 1s (encoding). Each pixel is translated in a way that the computer understands. Boolean values refer to values in which 0s and 1s are translated to "false" and "true".
In this activity, students created a monochrome image (a picture taken in grayscale) based off a binary table and Boolean encoding. The 0 (or "false") represents the white beads while the 1 (or "true") represents the black beads.
Technology is embedded throughout many aspects of our everyday lives. Students are increasingly interested in coding and other activities that technology affords. This workshop provides a high-level introduction to machine language, which is the basis for how computers operate.
- If some students finish early, give them a blank encoding sheet so they can create their own design (letters are often easier to translate to a tabular form). Incorporate place-based pedagogy by researching local symbols/discussing with the educator beforehand to appear to the students' interests.
- Older students might inquire how a computer can store an image with more than two colours. To store the colour value of each pixel, we need lots of "bits" (more than just one 0 or one 1). Grouping bits together allows us to represent more colours. For example, since binary is a base-two system, in an image with four colours, this can be represented as 2^2 (2^2=4. Meaning four values are used, where the bits can be represented in the following ways: 00, 01, 10, 11).
What's Happening?
Photographic images can be stored in a computer either in lines and shapes (vector images) or in pixels. Pixels are known as "picture elements" and arranged in a 2-dimensional array, in a format that computers understand. Computers understand information through "machine language" or "binary". In machine language, data is represented as 0s and 1s, known as bits. When a computer receives information, it must be translated into 0s and 1s (encoding). Each pixel is translated in a way that the computer understands. Boolean values refer to values in which 0s and 1s are translated to "false" and "true".
In this activity, students created a monochrome image (a picture taken in grayscale) based off a binary table and Boolean encoding. The 0 (or "false") represents the white beads while the 1 (or "true") represents the black beads.
Why Does It Matter?
Technology is embedded throughout many aspects of our everyday lives. Students are increasingly interested in coding and other activities that technology affords. This workshop provides a high-level introduction to machine language, which is the basis for how computers operate.
Investigate Further
- If some students finish early, give them a blank encoding sheet so they can create their own design (letters are often easier to translate to a tabular form). Incorporate place-based pedagogy by researching local symbols/discussing with the educator beforehand to appear to the students' interests.
- Older students might inquire how a computer can store an image with more than two colours. To store the colour value of each pixel, we need lots of "bits" (more than just one 0 or one 1). Grouping bits together allows us to represent more colours. For example, since binary is a base-two system, in an image with four colours, this can be represented as 2^2 (2^2=4. Meaning four values are used, where the bits can be represented in the following ways: 00, 01, 10, 11).