Alpine Rescue
I can decompose a rescue, reuse loops, and meet a battery constraint.
Your activities & worksheet
Two stranded research pods need help. Rescue both and return to base before the rover runs out of battery. Work with a partner, swap roles, and record your own thinking.
How do we plan a rescue that includes the return journey?
Activity 1 · Plan the rescue budget
- Open Alpine Rescue. Locate two pods and the shared start/base.
- Plan travel, rescue, return, and unload. Moves/rescues/unload cost 1 unit each; turns cost 0.5. Budget from 22.
Activity 2 · Rescue and return
- Build perimeter travel with Repeat 4 groups. Rescue at C5 R5 and C5 R1.
- Return to C1 R5, then Unload at base. Predict remaining battery and complete the mission.
Activity 3 · Investigate a limited resource
- Add three extra right turns and three left turns at the start. Predict the battery effect.
- Run and compare with the original route. Remove the wasted actions and retest.
Individual exit check
Why is reaching the second pod not the end of the rescue?
Teach this lesson
A 50-minute plan with preparation, prompts, model responses, differentiation, and an individual assessment.
How do we plan a rescue that includes the return journey?
| Planning element | Teacher notes |
|---|---|
| Learning target | I can decompose a rescue, reuse loops, and meet a battery constraint. |
| Evidence of learning | Collect both pods and unload at base using no more than 22 battery units. Keep individual predictions, observations, and an explanation; a completion badge alone does not establish mastery. |
| Standards focus | 2-3.CT.4, 2-3.CT.9, 2-3.CT.10; 4-6.CT.4, 4-6.CT.6, 4-6.CT.10. |
| Vocabulary | decomposition, constraint, battery, return, unload |
| Readiness | Follow a short sequence and use a grid. Revisit the previous week’s prediction and explanation before introducing this game. |
| Preparation | Open game-week-06.html (Alpine Rescue). Check the tracked rescue rover and Snowcap Rescue Base scene. Prepare a 5-by-5 grid, arrow counter, and worksheet. Use one device per pair and review the goal before revealing a solution. Game awards and worksheet responses save locally on this device; use teacher records for assessment. |
50-minute lesson sequence
| Minutes | Teaching moves | Look for |
|---|---|---|
| 0-5 | Introduce the mission Read the story and goal. Ask: How do we plan a rescue that includes the return journey? Identify what must be observed to verify success. | Learners restate the task and constraints. |
| 5-12 | Model one action or test Demonstrate one control without solving the whole game. Explain the difference between robot heading and camera view. Ask for a prediction before clicking Run. | Each learner names an input, expected action, and observable result. |
| 12-20 | Activity 1: Plan the rescue budget Open Alpine Rescue. Locate two pods and the shared start/base. Plan travel, rescue, return, and unload. Moves/rescues/unload cost 1 unit each; turns cost 0.5. Budget from 22. Ask pairs to trace with a counter before retesting. | Collect the first worksheet prediction and observation. |
| 20-35 | Activity 2: Rescue and return Build perimeter travel with Repeat 4 groups. Rescue at C5 R5 and C5 R1. Return to C1 R5, then Unload at base. Predict remaining battery and complete the mission. Swap driver and navigator after one run. Pause at the first unexpected state. | Both partners connect a block, label, or parameter with the observed result. |
| 35-43 | Activity 3: Investigate a limited resource Add three extra right turns and three left turns at the start. Predict the battery effect. Run and compare with the original route. Remove the wasted actions and retest. | A revision or comparison is supported by a recorded test. |
| 43-48 | Independent exit check Ask each learner: Why is reaching the second pod not the end of the rescue? Allow a spoken answer, drawing, or written response without a partner supplying the explanation. | Use the model answer as a guide; accept other explanations grounded in the run. |
| 48-50 | Save evidence and reflect Record completion and a next teaching step. Ask learners to download their worksheet or use a teacher-approved classroom record. | A next test or remaining limitation is named. |
Model program and expected behavior
repeat 4 { move }; rescue; left
repeat 4 { move }; rescue; left
repeat 4 { move }; left
repeat 4 { move }; left; unloadThe model route uses 16 moves, 4 left turns, 2 rescue actions, and 1 unload: 23 actions costing 21 battery units. One unit remains. Merely collecting both pods does not complete the rescue; unload requires both pods at base.
2D teaching reference
Columns run west to east; rows run north to south. S = start, G = goal, M = mission item, X = barrier, P = route. Start heading: east. Use counters and this grid as an alternative to interpreting the 3D view.
| Grid | C1 | C2 | C3 | C4 | C5 |
|---|---|---|---|---|---|
| R1 | P | P | P | P | PM |
| R2 | P | . | . | . | P |
| R3 | P | . | . | . | P |
| R4 | P | . | . | . | P |
| R5 | SG | P | P | P | PM |
Misconceptions and a useful response
| Misconception | Response |
|---|---|
| The rescue ends at the second pod. | Ask who still needs transport and where the base is. Include return and unload in the sub-task plan. |
| Finishing the game proves I understand everything. | Ask for an individual prediction, trace, explanation, and a next test. Use completion as one piece of evidence. |
Differentiate the task
Support: Give a perimeter map and a 22-unit token budget. Debit half-units with pairs of tokens or a number line. Provide the written position/heading status and a 2D or tactile map when the 3D view is not useful.
Extend: Remove the final left turn before Unload: the rover can unload facing south, so 1.5 units remain. Compare a valid alternative without claiming it is globally optimal.
Independent exit check
Prompt: Why is reaching the second pod not the end of the rescue?
Teacher key: The rover must carry both pods back and unload at base. Plan battery for the return trip.
Connect to Scratch or physical robotics
A real robot’s energy use is not a fixed per-action token cost. Treat the battery as a simplified planning model and identify factors it omits.