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Mathematics · Class 4

Active learning ideas

The 24-Hour Clock

Have you ever looked at a train ticket and wondered what time '17:30' means? Today, we will crack the code of the 24-hour clock used by railways and airlines to avoid any confusion!

CBSE Learning OutcomesNCERT Class 4 Mathematics: Chapter 4 - Tick-Tick-Tick
20–30 minPairs → Whole Class3 activities

Activity 01

Simulation Game25 min · Pairs

Railway Timetable Challenge

Provide students with simplified, authentic-looking Indian Railways timetables. Ask them to find specific trains, identify their departure and arrival times, and convert them from 24-hour to 12-hour format and vice-versa.

Explain why the 24-hour clock is used in some situations like train schedules.

Facilitation TipUse local train schedules to make the activity more relatable and engaging for the students.

What to look forExit Slip: Give each student a slip with a time in one format (e.g., '4:30 PM' or '19:45'). They must write the equivalent time in the other format before leaving the class.

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Activity 02

Simulation Game20 min · Whole Class

Human Clock

Draw a large circle on the floor. Have 12 students stand as numbers on a clock. Call out a time in 24-hour format (e.g., 15:00), and have other students move the 'hour' and 'minute' hands (students holding ropes) to the correct 12-hour position and say the time aloud.

Compare a time written in 12-hour format to its 24-hour equivalent.

Facilitation TipStart with simple hours and gradually introduce times with minutes to build confidence.

What to look forWorksheet with a mock bus timetable. Students answer questions that require them to read times, convert them, and calculate simple time durations.

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Activity 03

Simulation Game30 min · Individual

My 24-Hour Day

Students create a personal daily schedule, from waking up to sleeping, using only the 24-hour time format for all activities. They can draw pictures for each activity, making it a creative exercise.

Analyse a train timetable to determine departure times in both formats.

Facilitation TipEncourage students to include both school and home activities for a complete daily cycle.

What to look forProvide a checklist with 'I can' statements, such as 'I can tell the 24-hour time for 7 PM' or 'I can find a morning train on a timetable'. Students tick the skills they feel confident about.

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Templates

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A few notes on teaching this unit

Start by showing a clock with two rings of numbers, one for 1-12 and an outer one for 13-24. Demonstrate how the day continues counting past 12 noon. Use the simple rule: for any PM time, just add 12 to the hour to find its 24-hour partner. Practice with many examples before introducing real-world timetables.

By the end of this lesson, students will be able to confidently read any time in the 24-hour format and easily switch it back to the familiar 12-hour AM/PM time.


Watch Out for These Misconceptions

  • 12:30 in the afternoon is written as 24:30.

    The 24-hour clock only changes the hour, not the minutes. After 12:59 PM, the next hour is 13:00 (1 PM), not 24:00. 12:30 PM is simply 12:30 in the 24-hour format.

  • Midnight is always written as 24:00.

    While 24:00 can mean the end of a day, the start of a new day begins at 00:00. So, when we see a schedule, midnight is usually written as 00:00 hours.

  • You need to write AM or PM with 24-hour times, like 17:00 PM.

    The entire purpose of the 24-hour clock is to avoid using AM and PM. The number itself tells you if it's morning or afternoon. Any time from 13:00 to 23:59 is automatically in the afternoon or evening.


Methods used in this brief