Parcel Post
I can program a pickup and delivery in the correct order.
Your activities & worksheet
The meadow post office has a parcel waiting. Program your courier cart to collect it and deliver it to the purple house. Work with a partner, swap roles, and record your own thinking.
How does instruction order make a delivery succeed?
Activity 1 · Find the parcel
- Open Parcel Post. Locate C3 R3 and the destination at C5 R3.
- Run two moves and try delivery before pickup. Read the feedback; identify the missing action.
Activity 2 · Complete a delivery
- Build the route with a pickup at the parcel and a delivery at the house.
- Predict each cargo change, then Run. Swap roles and rebuild without copying.
Activity 3 · Debug the pickup
- Move Pick up one instruction earlier. Predict and test the failure.
- Use the trace to put pickup back at C3 R3 and complete a new delivery.
Individual exit check
Which instruction changes the parcel from waiting to being carried?
Teach this lesson
A 50-minute plan with preparation, prompts, model responses, differentiation, and an individual assessment.
How does instruction order make a delivery succeed?
| Planning element | Teacher notes |
|---|---|
| Learning target | I can program a pickup and delivery in the correct order. |
| Evidence of learning | Pick up the parcel at C3 R3 and deliver it to C5 R3. 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, 2-3.NSD.2. |
| Vocabulary | sequence, instruction, cargo, pickup, delivery, debug |
| Readiness | Follow a short sequence and use a grid. No previous Scratch experience is required. |
| Preparation | Open game-week-01.html (Parcel Post). Check the courier cart and Meadow Mail 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 does instruction order make a delivery succeed? 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: Find the parcel Open Parcel Post. Locate C3 R3 and the destination at C5 R3. Run two moves and try delivery before pickup. Read the feedback; identify the missing action. Ask pairs to trace with a counter before retesting. | Collect the first worksheet prediction and observation. |
| 20-35 | Activity 2: Complete a delivery Build the route with a pickup at the parcel and a delivery at the house. Predict each cargo change, then Run. Swap roles and rebuild without copying. 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: Debug the pickup Move Pick up one instruction earlier. Predict and test the failure. Use the trace to put pickup back at C3 R3 and complete a new delivery. | A revision or comparison is supported by a recorded test. |
| 43-48 | Independent exit check Ask each learner: Which instruction changes the parcel from waiting to being carried? 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
move; move; pick up; move; move; deliver
Six actions: move twice, pick up, move twice, deliver. The parcel remains on the tile until pickup. Delivery requires both the correct location and carried cargo.
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 | . | . | . | . | . |
| R2 | . | . | . | . | . |
| R3 | S | P | PM | P | G |
| R4 | . | . | . | . | . |
| R5 | . | . | . | . | . |
Misconceptions and a useful response
| Misconception | Response |
|---|---|
| Moving over a parcel collects it. | Test moving past it without Pick up. Ask the learner to name the missing state-changing action. |
| 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: Use six illustrated action cards and a parcel counter. Ask learners to arrange the cards and explain the pickup position. Provide the written position/heading status and a 2D or tactile map when the 3D view is not useful.
Extend: Compare a route plan grouped as travel / collect / travel / deliver with the same six individual actions. Explain why the order cannot be arbitrary.
Independent exit check
Prompt: Which instruction changes the parcel from waiting to being carried?
Teacher key: Pick up at C3 R3. Moving across the parcel does not collect it automatically.
Connect to Scratch or physical robotics
In Scratch, use a cargo variable and touching-destination condition. A physical gripper would need an explicit pickup action and a successful-grip check.