What Is an Algorithm?
Students will program a block code algorithm for navigating a virtual maze.
- To introduce this lesson, you will be acting out a scenario in which you demonstrate the concept of algorithm.
- Place an object, like a coffee mug, on a desk or table and then take a few steps back.
- Tell your students, "I need my coffee mug but I can't reach it from here. What should I do?"
- Students will make suggestions like, "Walk over there and get it." Challenge students to be more specific by asking, "How many steps should I take?"
- Once you have successfully reached the coffee mug, recap the instructions that the students offered. "Your instructions were to walk three steps forward."
- Tell your students that this is an example of an algorithm: a sequence of step-by-step instructions.
- Explain that computer programmers create algorithms using code, and today they are going to learn to create their own algorithms using a code called Blockly.
- Give students time to ask questions to request more information about algorithms, the topic of coding, or Blockly.
Explicit Instruction/Teacher modeling(5 minutes)
- Divide students into pairs and pass out devices.
- Show students how to turn on the devices and access the website.
- Ask students to select "Maze."
Guided Practice(5 minutes)
- Once the Maze game is open, ask students to describe and identify what they see: On the left will be an area that looks like a map, in the middle, an area with several purple "blocks" of code. Each block is labeled with words like "move forward" or "turn right." On the right is an open area where they will build your code. There is also a red button labeled "Run program."
- Ask students, "What do you think you'll need to do to complete this maze?"
- Invite students to take turns solving the maze.
- Allow students to ask each other clarifying questions about how to use the program to get a better understanding of how to navigate the maze:
- "Can you give me more details about ____?"
- "Can you remind me how to...?"
- "How do I...?"
Independent working time(20 minutes)
- Invite the pairs of students to take turns using the device until both students have had a chance to try each level.
- If your students have not shared a device before, they will need some ground rules for how to take turns. Review group work expectations and how to have peer discussions in a respectful manner.
- For students who progress quickly through all the levels, invite them to try one of the other categories of Blockly games, such as Bird or Turtle.
- For students who struggle with fine motor skills, using a cursor or mouse may be difficult. These students would benefit from using a touch screen on a tablet. Instead of Blockly, which is web-based, try an educational coding app like Kodable or Lightbot.
- Circulate the room and observe each pair of students working together.
- Measure student success by whether or not each student is able to complete at least one level of the maze.
Review and closing(5 minutes)
- Ask students to reflect on their experience creating algorithms.
- What was fun about this activity?"
- “What was challenging?"
- Invite peer to peer feedback by asking, “How did your partner help you learn? Did it help to ask your partner clarifying questions?"
Ann Gadzikowski is an author and educator with a passion for challenging children to think creatively and critically. Her recent book Robotics for Young Children won the 2018 Midwest Book Award for best educational book. Ann developed her expertise in robotics, computer science, and engineering through her work as early childhood coordinator for Northwestern University’s Center for Talent Development. She has over 25 years of experience as a teacher and director of early childhood programs, and currently serves as the Executive Director of Preschool of the Arts, a Reggio-Emilia inspired school in Madison, Wisconsin.