Hāngi Time Investigators

Overview

Students use analogue and digital clocks, a timeline, and familiar events to measure and calculate duration in hours. They apply their understanding to determine when the hāngi was put down, building on prior learning about reading times and sequencing daily events.

Learning intentions

• WALT measure duration in whole hours.
• WALT use a timeline to show the order and duration of events.
• WALT connect analogue and digital times.
• WALT calculate a finishing time from a starting time and duration.

Success criteria

• I can read and record a time in hours using an analogue or digital clock.
• I can place events in order on a timeline.
• I can calculate a time one or more hours before or after an event.
• I can explain how I know when the hāngi was put down.

Curriculum links

• Measurement — use familiar events as benchmarks to estimate and measure duration using appropriate time-based units.
• Mathematics and Statistics — Mathsteasers: solve higher-order questions and explain reasoning.
• Mathematics and Statistics — Mathsteasers / Alignment: connect time calculations with familiar textbook learning.
• Te Mātaiaho — communicate mathematical thinking using diagrams, number sentences and explanations.

Lesson structure (30 minutes)

1. 0–4 min · Hook and estimate. Display a simple daily timeline showing preparation for a hāngi and ask, “At what time did they start putting the hāngi down?” Open with the hāngi time investigation hook. Students make a quiet estimate, then share what information they would need to be certain.

2. 4–9 min · Revisit time vocabulary. Use the time vocabulary and clock examples to review hours, minutes, analogue, digital, 24 hours, timeline and calculate. Teacher models that one complete movement from one hour number to the next represents one hour, while students read selected analogue and digital times aloud with a partner.

3. 9–14 min · Model a timeline. Teacher presents the hāngi information from Maths No Problem! Textbook 4B, pages 94–96, and models placing the known events on a timeline. Think aloud while counting forwards or backwards in whole hours, asking, “What is the starting time? What is the duration? What time must we find?” Students help complete one example and explain the calculation.

4. 14–23 min · Guided workbook practice. Distribute the time investigation worksheet and direct students to complete the relevant tasks alongside Workbook pages 65–66. Students work independently for two minutes, then compare methods with a partner. Teacher circulates, checking that students use the hour hand correctly, distinguish analogue and digital representations, and show jumps on a timeline.

5. 23–27 min · Discuss and justify. Reveal the investigation answer using the worked hāngi timeline and discussion prompts. Students compare answers, identify any different but valid strategies, and complete the sentence: “The hāngi was put down at ___ because ___.” Address the common error of counting clock numbers rather than elapsed hours.

6. 27–30 min · Exit check. Show a final time problem on the final check and reflection: “The hāngi was put down at 9 o’clock and took 3 hours to cook. What time was it ready?” Students record an analogue clock, digital time and one calculation on the worksheet, then hand it in as they leave.

Resources

• the hāngi time investigation slide deck
• the time investigation worksheet
• Maths No Problem! Textbook 4B, pages 94–96
• Maths No Problem! Workbook, pages 65–66
• Demonstration analogue clock with movable hands
• Mini analogue clocks or paper clock faces, one per pair
• Whiteboard and markers
• Pencils and rulers

Assessment

• Listen during the hook and vocabulary review for accurate use of hours, minutes, analogue, digital and timeline.
• During workbook practice, check whether students identify the starting time, represent whole-hour jumps and calculate accurately.
• Use the exit check to identify students who can connect a duration, timeline and finishing time. Note students needing further support with reading the hour hand or counting elapsed hours.

Differentiation

• Support students with a large demonstration clock, a movable mini-clock and a partially completed timeline. Encourage them to mark each one-hour jump and use the sentence frame, “I started at ___ and counted ___ hours.”
• Pair students strategically for oral rehearsal before writing. Provide visual word cards for hours, minutes, analogue, digital, timeline and calculate, with clear examples.
• For students ready for challenge, ask them to solve the hāngi problem using both forwards and backwards counting, then create a similar problem with a different starting time and duration.
• For EAL learners and students requiring additional support, use gestures and images for event order, read each question aloud, reduce the number of problems without reducing the mathematical thinking, and accept an oral explanation alongside written work.