Metric Obstacle Challenge

Overview

Students design and then navigate a simple obstacle course using measurement clues written in different units. They collaboratively convert distances to a common unit (metres), estimate distances, and time each attempt to apply practical metric measurement in a real-world context.

Learning intentions

• Students will measure and compare lengths using appropriate metric units.
• Students will convert between common metric units of length to solve measurement clues.
• Students will estimate distances before measuring to check reasonableness.
• Students will use timing data to reflect on how measurement choices affect navigation accuracy.

Success criteria

• I can convert distances given in cm, m, and km into the same unit (metres).
• I can choose the correct measuring tool/device and record measurements accurately.
• I can estimate a distance and explain whether my measured value is reasonable.
• I can navigate the course by following converted clues and track my time fairly.

Curriculum links

• Geometric measure B — MA3-GM-02: Students select and use the appropriate unit and device to measure lengths and distances including perimeters.
• Measurement focus within Stage 3: converting between common metric units of length and solving comparisons using appropriate units.
• Apply measurement to a real context: designing a course with measurable stations and perimeter-like boundaries where relevant (e.g., outlining the course path).

Lesson structure (90 minutes)

1. 0–10 min · Hook and model. Teacher shows 3 clue cards with mixed units (e.g., “Go 250 cm”, “Move 1.2 m”, “Next marker: 0.06 km”) and one example conversion to metres; students discuss: “What unit should we use so clues match?” Students think-pair-share the common unit and estimate how far each would be.

2. 10–25 min · Mini direct teach: converting and estimating. Teacher models a short conversion routine: identify the target unit (metres), choose the conversion strategy (cm→m, mm→cm if needed, km→m), then check reasonableness using estimation. Students complete 4 teacher-guided practice conversions on mini whiteboards and record a quick “reasonable?” comment.

3. 25–35 min · Planning the obstacle course (teams). Teacher explains the task: each group will create a 5-station obstacle course with distance clues written in different units, but all convertible to metres. Stations must be measurable using available equipment (tape measures, metre rulers, string). Students, in groups of 4, sketch the course on paper, label stations A–E, and decide what unit mix they will include (e.g., one clue in cm, one in m, one in km, etc.).

4. 35–55 min · Build and measure stations. Teacher sets clear safety and fairness rules for movement through obstacles. Teacher circulates to support selecting units and devices. Students measure each station-to-station distance using a tape measure/string, record both the original unit and the converted distance to metres, and write the clues for the navigator.

5. 55–65 min · Peer-check conversion accuracy. Teacher gives each group a “checklist card”: target unit is metres; conversion steps shown; estimate compared to measurement; clue distance matches the recorded conversion. Students swap clue sheets with another group and verify conversions, pointing out one strength and one error or improvement.

6. 65–80 min · Navigate the course with timing. Teacher demonstrates how to time fairly (start when navigator leaves Station A; stop at Station E; record to nearest second where possible). Students take turns: one navigator follows the clues (using only converted metres), while a partner times and another records the start/finish times and any navigation mistakes; rotate roles.

7. 80–90 min · Data discussion and exit reflections. Teacher leads a brief class discussion: “Did the conversion help you move accurately? What caused delays—misread units, estimation mismatch, or distance too close to another station?” Students complete a short exit reflection: one conversion they found challenging and one strategy they used to check reasonableness.

Resources

• Cones/markers for stations A–E
• Measuring tapes (metre units) and/or string with ruler markings
• Metre rulers or 1-m folding rulers
• Clipboards, recording sheets, and pen/pencils
• Mini whiteboards and markers
• Timing devices (stopwatches or phone timers with teacher permission)
• Course sketch paper and “conversion check” checklist cards
• Obstacle items (e.g., agility ladder, foam blocks, beanbags) that do not require lifting or hazards

Assessment

• Formative during conversions (teacher checks whiteboard answers and reasoning comments).
• Observational checklist while building and measuring (correct unit choice, accurate recording, appropriate device).
• Exit reflection (shows understanding of conversion to metres and estimation/reasonableness strategy).

Differentiation

• Support: provide a conversion table (cm↔m, km↔m) and sentence starters: “I chose metres because…” “My estimate was about…, and my measurement was…”
• Support: give smaller-step clues first for early finishers (e.g., only cm and m, then extend to km if time allows within group choice).
• Extension: challenge groups to include a perimeter-style component by adding a boundary segment and asking navigators to follow total distance across a “rounded route” (students must still convert and record metres).
• EAL/SEN: use visual unit cues (coloured labels for cm, m, km) and allow oral explanation of conversion steps alongside written work.