By the end of this chapter you'll be able to…

  • 1Name the units of time and how they relate
  • 2Read o'clock and half past on a clock
  • 3Tell the hour hand from the minute hand
  • 4Read days, dates, and months on a calendar
  • 5Solve simple time questions
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Why this chapter matters
Time Goes On teaches children to read clocks and calendars and to use the units of time. Telling o'clock and half past, knowing the days of the week and months of the year, and understanding how time units fit together build everyday independence.

Before you start — revise these

A 5-minute refresher here will save you 30 minutes of confusion below.

Time Goes On — Class 3 Mathematics (CBSE)

From the current NCERT Maths Mela Grade 3 book, Chapter 13. Clocks and calendars help us tell time and plan our day.


1. Why this chapter matters

Time runs our day — when we wake, study, eat, and sleep. Learning to read a clock and a calendar, and to know how seconds, minutes, hours, days, and months fit together, helps children become organised and independent.

2. Core ideas

Idea 1 — The units of time

60 seconds = 1 minute, 60 minutes = 1 hour, 24 hours = 1 day, 7 days = 1 week, 12 months = 1 year.

Method 2 — Read the clock

The short hand shows the hour; the long hand shows the minutes. Long hand on 12 = o'clock; on 6 = half past.

Skill 3 — Read the calendar

A calendar shows the days of the week and the months of the year, and helps us find dates.

3. Worked examples

Example 1: The short hand is on 3 and the long hand on 12. What time is it?

It is 3 o'clock.

Example 2: The short hand is between 4 and 5, the long hand on 6. What time?

It is half past 4 (4:30).

Example 3: How many days are there in a week, and how many months in a year?

7 days in a week and 12 months in a year.

4. Activity corner

Make a paper clock with two hands. Set it to show 2 o'clock, half past 7, and your school start time. Then circle today's date on a calendar. Write:

  • The times I showed
  • Today's day and date
  • The maths idea (reading clocks and calendars)

5. Common mistakes

  • Mistake: Mixing up the hour hand and the minute hand. Fix: The short hand = hour, the long hand = minutes.
  • Mistake: Saying "half past" without moving the hour hand. Fix: At half past, the hour hand sits between two numbers.
  • Mistake: Forgetting the number of days or months. Fix: Remember 7 days in a week and 12 months in a year.

6. How to write better answers

  1. Look at the short hand for the hour.
  2. Look at the long hand for o'clock or half past.
  3. For the calendar, find the day, date, and month.
  4. Use the correct unit (minutes, hours, days).

7. Practice set

  1. How many minutes are there in one hour?
  2. The short hand is on 8 and the long hand on 12. What time is it?
  3. How many days are there in one week?
  4. How many months are there in one year?
  5. What time is half past 6?
  6. How many hours are there in one day?

8. Answer key

  1. 60 minutes in one hour.
  2. 8 o'clock.
  3. 7 days in one week.
  4. 12 months in one year.
  5. Half past 6 is 6:30.
  6. 24 hours in one day.

9. Quick revision

  • 60 seconds = 1 minute; 60 minutes = 1 hour; 24 hours = 1 day.
  • 7 days = 1 week; 12 months = 1 year.
  • Short hand = hour; long hand = minutes.
  • Long hand on 12 = o'clock; on 6 = half past.
  • A calendar shows days, dates, and months.

Key formulas & results

Everything you need to memorise, in one card. Screenshot this for revision.

Core idea
60 seconds = 1 minute; 60 minutes = 1 hour; 24 hours = 1 day; 7 days = 1 week; 12 months = 1 year.
These units fit together in fixed amounts.
Math move
Short hand shows the hour; long hand shows the minutes.
Long hand on 12 is o'clock; on 6 is half past.
Exam habit
A calendar shows the days of the week and the months of the year.
Use it to find days and dates.
⚠️

Common mistakes & fixes

These are the exact errors that cost students marks in board exams. Read them once, save yourself the trouble.

WATCH OUT
Mixing up the hour hand and the minute hand
The short hand shows the hour; the long hand shows the minutes.
WATCH OUT
Saying half past without moving the hour hand
At half past, the hour hand sits between two numbers.
WATCH OUT
Forgetting the number of days or months
Remember 7 days in a week and 12 months in a year.

Practice problems

Try each one yourself before tapping "Show solution". Active recall > rereading.

Q1EASY· Units
How many minutes are there in one hour?
Show solution
60 minutes.
Q2EASY· Clock
The short hand is on 8 and the long hand on 12. What time is it?
Show solution
8 o'clock.
Q3EASY· Calendar
How many days are there in one week?
Show solution
7 days.
Q4EASY· Calendar
How many months are there in one year?
Show solution
12 months.
Q5MEDIUM· Clock
What time is half past 6?
Show solution
6:30 (the hour hand is between 6 and 7, the minute hand on 6).
Q6MEDIUM· Units
How many hours are there in one day?
Show solution
24 hours.

5-minute revision

The whole chapter, distilled. Read this the night before the exam.

  • Time Goes On is Chapter 13 of the Class 3 Maths Mela textbook.
  • 60 seconds = 1 minute; 60 minutes = 1 hour; 24 hours = 1 day.
  • 7 days = 1 week; 12 months = 1 year.
  • Short hand = hour; long hand = minutes.
  • Long hand on 12 = o'clock; on 6 = half past.
  • A calendar shows days, dates, and months.

CBSE marks blueprint

Where the marks come from in this chapter — so you can plan your prep.

Typical chapter weightage: 3-4 marks in school tests, oral checks, notebooks, and activities

Question typeMarks eachTypical countWhat it tests
Very Short12-3Time units, o'clock readings, days, or months
Short Answer21-2Half past readings or relating time units
Activity / Project30-1Making a clock and reading a calendar
Prep strategy
  • Practise reading o'clock and half past on a clock
  • Learn the units of time and how they connect
  • Recite the days of the week and months of the year
  • Use a calendar to find dates

Where this shows up in the real world

This chapter isn't just an exam topic — it lives in the world around you.

Planning the day

Reading a clock helps children follow timetables and routines.

Using a calendar

Finding days and dates helps plan holidays, birthdays, and events.

Being on time

Knowing time units builds punctuality and independence.

Exam strategy

Battle-tested tips from teachers and toppers for this chapter.

  1. Underline the command word: what time, how many, or which day
  2. Read the short hand first for the hour
  3. Use the right unit (minutes, hours, days)
  4. For half past, place the minute hand on 6

Going beyond the textbook

For olympiad aspirants and curious learners — topics that build on this chapter.

  • If school starts at 8 o'clock and lasts 5 hours, when does it end?
  • Name the month that comes two months after September.

Where else this chapter is tested

CBSE board isn't the only one — other exams test this chapter too.

CBSE Class 3 School AssessmentHigh
Class 3 Foundation / Olympiad PracticeMedium
Notebook and Activity EvaluationHigh

Questions students ask

The real ones — pulled from the Q&A community and tutor sessions.

The short hand is the hour hand and the long hand is the minute hand. When the long hand points to 12, it is o'clock.

Half past means 30 minutes after the hour. The minute hand points to 6 and the hour hand sits between two numbers.
Verified by the tuition.in editorial team
Last reviewed on 31 May 2026. Written and reviewed by subject-matter experts — read about our process.
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