Finding Durations Between Times

Overview

This 45-minute lesson is the final session in the Year 5 unit Mastering Time Calculations, designed to securely embed students' understanding of calculating durations between two given times. It aligns with the Curriculum for Wales framework, focusing on developing numerical reasoning and problem-solving through real-life contexts involving time.

Curriculum for Wales Links

Area of Learning and Experience (AoLE): Mathematics and Numeracy

• Learning Area: Units, Measurement and Geometry
• Learning Outcome: 5P_MS_05 — Use common units of time to solve problems, including calculating durations.
• Cross-curricular competences:
  • Numeracy: Applying arithmetic operations in practical contexts.
  • Creativity and Innovation: Planning activities and exploring efficient scheduling.
  • Thinking: Developing strategies to solve time subtraction problems.

---

Learning Objectives

By the end of the lesson, pupils will be able to:

1. Calculate the duration between two given times using subtraction of hours and minutes.
2. Apply subtraction strategies to find durations in both simple and compound time problems.
3. Use reasoning to explain their methods for calculating durations.
4. Use their knowledge in practical, real-life scenarios such as event or activity planning.

---

Success Criteria

• I can subtract hours and minutes to calculate the duration between two times accurately.
• I can explain the steps I took to solve the time calculation.
• I can apply my skills to plan or analyse real-life schedules.

---

Resources

• Whiteboard and marker pens
• Clock visuals (analogue and digital)
• Printed worksheets with time subtraction problems and real-life scenarios
• Step-by-step subtraction guides (for differentiation)
• Schedule templates for extension activity
• Stopwatches/timers (optional kinaesthetic element)

---

Lesson Structure

1. Starter / Recap (7 minutes)

• Quick recap of key vocabulary: duration, start time, end time, hours, minutes.
• Refresh subtraction of time: Model on whiteboard subtracting minutes and hours separately (e.g., 3:45 pm – 2:20 pm).
• Use an interactive “show of hands” to check confidence and understanding.

2. Teaching Input (10 minutes)

• Explicitly teach strategies for subtracting time, including:
  • Partitioning minutes and hours, borrowing 1 hour as 60 minutes when needed.
  • Using a blank number line to visualise the calculation.
• Pose a problem on the board: “An event starts at 4:35 pm and finishes at 6:15 pm. How long did it last?”
• Work through the steps together, modelling the reasoning and explaining why we borrow or partition.

3. Guided Practice (10 minutes)

• Pupils complete 3 differentiated problems in pairs:
  • Support level: Use step-by-step guide sheets and peer support. Problems with whole hour differences and simple minutes subtraction.
  • Expected level: Problems with mixed hours and minutes subtraction, includes borrowing.
  • Challenge: Problems with times crossing midday/noon or midnight (e.g., 11:50 am to 1:15 pm).
• Teacher circulates, offering scaffolded support and asking students to verbalise their reasoning.

4. Application to Real-Life Context (10 minutes)

• Introduce a scenario: planning a school event or after-school activity (e.g., how long will different games or acts last?).
• In groups of 3-4, pupils calculate durations between scheduled event times from a provided timetable.
• Challenge: Advanced learners analyse multiple activities’ durations and discuss the most efficient order to fit all within a time frame. They can rearrange events on a schedule template to maximise available time.

5. Plenary and Assessment (8 minutes)

• Select 3 volunteers to explain to the class how they found the duration between two times on their worksheet or schedule – focusing on their reasoning.
• Recap success criteria and ask pupils to vote: “Do you feel confident calculating time durations now? What helped you?”
• Use a quick exit ticket: Write down one strategy they found helpful for subtracting times.

---

Differentiation Strategies

• Provide step-by-step subtraction guides with visual aids for students who need extra help.
• Allow peer support and paired work to encourage verbalisation of process and error checking.
• Provide concrete manipulatives (clock models, number lines) for learners needing kinaesthetic reinforcement.
• Simplify language and focus on basic calculations for those with less confidence.

---

Extension Activities for Advanced Learners

• Analyse complex schedules with overlapping events and calculate total time spent in activities and breaks.
• Plan a full day’s programme with fixed start and end times by arranging events to fit efficiently without overlap.
• Explore concepts of 24-hour time subtraction and crossing from AM to PM or vice versa.
• Use digital tools/apps to simulate scheduling and test different arrangements.

---

Notes for Teachers

• Encourage mathematical talk throughout the lesson to support reasoning development, a key aspect of Curriculum for Wales.
• Emphasise problem-solving with real-life contexts to foster the relevance and application of maths skills.
• Use formative assessment throughout by circulating and noting misconceptions for review next lessons.
• Celebrate all progress in understanding time subtraction, regardless of accuracy, to build confidence and resilience.

---

This lesson is designed to be engaging, scaffolded, and aligned precisely to Curriculum for Wales goals, embedding mastery of time calculations through varied, practical, and collaborative learning experiences.