Race for the Catch

Basic understanding of directionality (left, right, up, down)

Minds On: 10 minutes

• Let's read about some interesting facts about bears and salmon before we begin
• “When bears eat salmon and leave their carcass to decompose, it provides essential nutrients for the healthy growth of trees.”
• “Those trees in turn provide shade to the water stream, providing the perfect temperature for salmon spawning and maintaining the health of the water.”
• “Bears, on average, consume about 13 salmon per day during the 45 to 60 days long salmon spawning season.”

Model: 15 minutes

• Navigate to scratch.mit.edu and demonstrate the user interface: Explain the main areas (Stage, Sprite List, Backdrop Pane, Code Area, Block Categories such as Events, Control, Variables).
• Show how to add and remove sprites and backdrops: Select a bear, salmon, and forest background, and demonstrate resizing and positioning.
• Demonstrate basic sprite movement: Show how to use move steps and point towards mouse-pointer blocks to control a sprite, simulating the grizzly bear's movement.

Practice: 25 minutes

Teacher Guidance: Access the core activity. Guide students through the steps below, encouraging prediction and troubleshooting as they go.

Activity 1: Setting up the Game Environment (10 minutes)

• Instructions: Students will open Scratch, start a new project, and select the necessary sprites (e.g., a grizzly bear, a black bear, and a salmon) and a suitable backdrop (e.g., a forest or river setting). They will resize and position their sprites appropriately for the game.
• Teacher Lead: Circulate to assist students with sprite selection and initial setup. Encourage them to explore different options but keep the core elements of the game in mind. Remind them to save their project periodically.

Activity 2: Coding Bear Movement and Salmon Catch (15 minutes)

• Instructions: Students will first code the grizzly bear to follow the mouse pointer continuously. Next, they will program the salmon to appear at random locations on the screen. Finally, they will add a conditional statement to the salmon's code so that when it touches the grizzly bear, its position resets to a new random location.
• Teacher Lead: Guide students through creating the scripts, focusing on the use of forever loops for continuous movement and if then conditional blocks for the salmon. Encourage students to test their code frequently and debug any issues by reading their code and predicting outcomes. Provide support in setting up simple variables for scoring at this stage if time permits, or explicitly state it as the next step in the activity link.

Consolidate: 10 minutes

Facilitate a Circle Share where students take turns sharing one aspect of their game, a specific coding concept they used, or a challenge they successfully overcame during the activity.

Reflection Questions:

• What was challenging about coding the bear chase game, particularly implementing the scoring or movement?
• How did using variables help keep track of the score in your game?
• How is the concept of a "conditional statement" in Scratch similar to making decisions in everyday life?
• What other features or animations would you like to add to your game if you had more time?

1. Post key vocabulary with visuals (sprite, backdrop, loop, conditional, variable) and keep it visible throughout the lesson.
2. Provide short how-to videos for each major coding step so students can replay instructions independently.
3. Offer a simplified starter project (grizzly already moves; students only code salmon + scoring) for learners who need extra support.