Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

What you need:
IWB/Projector/Large Screen

Elapsed Time Within an Hour

Learn to work out how long a journey takes by counting on through the next hour-mark. We'll apply this to real Dublin Bus scenarios and explore when the hour-bridge strategy helps most.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Sketch the Number Line in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~4 mins

Illustration for Getting Started

Starter problem

A Dublin Bus leaves the school stop at 8:47 and pulls into town at 9:25. How long did the journey take?

The trick

This catches everyone out at first. The trick is not to add the digits in your head and panic, it's to break the journey at the next hour-mark. We'll learn the move today, then apply it to four real bus journeys.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~8 mins

Watch four elapsed-time examples on the IWB. The first one bridges the hour at 9:00; the second and third stay inside the same hour; the fourth lands cleanly on the next hour.

Example 1: 8:47 to 9:25, 38 minutes

From 8:47, count 13 minutes up to 9:00. Then count 25 minutes past 9:00 to 9:25. Total: 13 + 25 = 38 minutes.

Example 2: 10:15 to 10:55, 40 minutes

Same hour the whole way. Count on in fives from :15 to :55. Total: 40 minutes.

Example 3: 2:05 to 2:50, 45 minutes

Same hour. From :05 to :50 is 45 minutes.

Example 4: 6:30 to 7:00, 30 minutes

Half-hour exactly. The end time lands on the hour-mark, so the count is clean: 30 minutes.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~11 mins

We'll work through these together as a class. Each card shows a start time and a number of minutes to count on. Pupils take turns at the board; the class talks each one through before tapping the matching time.

Counting on in minutes

+15 XP

4 - Sketch the Number Line in Your Copy ~2 mins

COPYBOOK MOMENT

Illustration for Sketch the Number Line in Your Copy In your maths copy, work each elapsed-time problem on a sketched number line. Mark the start and end times on the line, count up to the next hour first, then on to the end. Write the total minutes underneath each one.

7:35 to 8:10
11:20 to 11:55
3:48 to 4:15

+10 XP

Pupil practice

Module 5 · Time and Money Measures

Lesson 59 · Elapsed Time Within an Hour

Download Activity Book page (PDF)

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