ANZAC Biscuit Time

Overview

Students investigate how long ANZAC biscuits were in the oven by reading analogue and digital times, using a timeline, and calculating duration in minutes. The lesson builds on familiar time language and connects duration to a real-life baking context from Maths — No Problem! Textbook 4B, pages 97–100, and Workbook pages 67–68.

Learning intentions

• WALT read and record times using analogue and digital clocks.
• WALT use a timeline to work out how many minutes have passed.
• WALT calculate and explain the duration of an event.
• WALT use hours, minutes and 24-hour time appropriately.

Success criteria

• I can read an analogue and digital time.
• I can mark start and finish times on a timeline.
• I can calculate how long the biscuits were in the oven.
• I can explain my strategy using words, drawings or a number sentence.

Curriculum links

• Measurement — estimate and measure duration using appropriate time-based units.
• Measurement — use familiar benchmarks to reason about the duration of events.
• Mathsteasers — use higher-order thinking and explain mathematical reasoning.
• Mathematical practices — represent, calculate, communicate and justify solutions.

Lesson structure (30 minutes)

1. 0–4 min · Hook and estimate. Open with the ANZAC biscuit hook slide showing a tray of biscuits and the question, “How long do you think ANZAC biscuits usually stay in the oven?” Students make a quick estimate in minutes, share with a partner, and explain what helped them decide.

2. 4–9 min · Review time language. Use the time vocabulary and clock slides to revisit hours, minutes, analogue, digital and 24 hours. Teacher models that the minute hand shows minutes and the hour hand shows the hour, then displays 2:35 in both forms. Students read two example times and identify which is earlier and later.

3. 9–15 min · Model a timeline. Introduce the textbook context: the biscuits went into the oven at 10:45 and came out at 11:20. On the board and the worked timeline slide, mark both times and count on in friendly jumps: 10:45 to 11:00 is 15 minutes, then 20 minutes to 11:20. Students help calculate the total duration and record the matching number sentence: 15 + 20 = 35 minutes.

4. 15–23 min · Guided textbook and workbook task. Distribute the ANZAC biscuit time investigation sheet for students to use alongside Textbook 4B pages 97–100. In pairs, students solve selected examples by drawing timelines, reading clocks and calculating durations; they then complete the related practice on Workbook pages 67–68. Teacher circulates, asking, “What is the start time?”, “What is the finish time?” and “Which hour boundary do you need to cross?”

5. 23–27 min · Discuss strategies. Bring the class together using the strategy discussion slides. Invite two pairs to explain different methods, such as counting on, using a timeline or subtracting minutes. Check that students distinguish the time of day from the duration and use “minutes” in their answers.

6. 27–30 min · Exit check. Display the final question on the plenary and exit-question slide: “A batch goes into the oven at 1:50 pm and comes out at 2:25 pm. How long was it in the oven?” Students complete the answer on the bottom of the ANZAC biscuit time investigation sheet, showing a timeline or calculation, then hand it in as they leave.

Resources

• Maths — No Problem! Textbook 4B, pages 97–100
• Maths — No Problem! Workbook, pages 67–68
• the complete time investigation slide deck
• the ANZAC biscuit time investigation sheet
• Analogue demonstration clock
• Mini analogue clocks or paper clocks, one per pair
• Whiteboard and markers
• Pencils and coloured pencils

Assessment

• Listen for accurate use of hours, minutes, analogue, digital and duration during partner talk.
• Check pair work for correctly identified start and finish times, sensible timelines and calculations that cross an hour boundary accurately.
• Use the exit question to identify whether students can calculate duration independently and include an appropriate unit.

Differentiation

• Support students with a demonstration clock, a visible 5-minute counting pattern and a partially completed timeline. Allow them to count on in two stages rather than subtracting directly.
• Pair students strategically and provide sentence starters: “The event started at…”, “It finished at…”, and “The duration was… because…”.
• For students needing additional support, use times to the nearest five minutes and rehearse the hour boundary with concrete clock movements before completing the workbook task.
• Extend confident students by asking them to find two possible start times for a 35-minute baking duration, or to explain why 60 minutes equals one hour and how this relates to 24 hours in a day.
• Provide visual vocabulary cards and read instructions aloud for EAL learners or students with literacy needs. Accept oral explanations, labelled drawings or number sentences as evidence of understanding.