CBSE Class 3 · Mathematics
Time Goes On
Official NCERT chapter from Maths Mela (book code cemm1). ExamMaster notes are original teaching at CBSE Class 3 depth.
This lesson follows the official chapter “Time Goes On” in Maths Mela. The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.
- CBSE Class 3
- Easy level
- 8 concepts
1A calendar missing July is a broken month-cycle
The year-cycle needs every month in order. A calendar that skips July cannot place August honestly.
A pretty calendar with a hole is still broken.
Figure. A year list with a hole cannot place August honestly. July is the missing name; the other eleven boxes are present.
How it works
- List months in orderJanuary to December.
- Find the missing nameA hole in the cycle.
- Refuse to date across the holeFix the list first.
2Months have an order that repeats each year
After December comes January again. That repeat is a new year, not a new month-name invented.
You do not get a thirteenth month by waiting.
Figure. December is followed by January again. That wrap is a new year, not a thirteenth month-name.
How it works
- Say the last monthDecember.
- Say the nextJanuary.
- Call that a new year if you crossed DecemberSame twelve names.
3Days of the week repeat every seven
After Sunday comes Monday again. Seven names, then the cycle.
An eighth weekday name is a miss.
Figure. Seven weekday names, then the cycle. After Sunday the next name is Monday again — not an eighth weekday.
How it works
- Name todayOne of seven.
- Count seven daysYou return to the same name.
- Use that to find “next Friday”Count along the cycle.
4Yesterday and tomorrow sit on the calendar
Yesterday is the box before today. Tomorrow is the box after. They are neighbours, not feelings.
“Yesterday” is not a duration of many days.
Figure. Yesterday and tomorrow are the neighbour boxes of today. They are places on the calendar, not feelings and not a long duration.
How it works
- Find today’s boxThe date you mean.
- Step one box backYesterday.
- Step one box forwardTomorrow.
5Duration is how long, not what date
“Three days” is a duration. “12 March” is a date. Do not mix them in one sentence without saying which you mean.
A date does not tell how long a game lasted.
Figure. Three days is a span you can bracket. 12 March is one calendar cell. Do not answer a how-long question with a date.
How it works
- Ask date or how longTwo different questions.
- If how long, count the spanDays, hours later.
- If date, point to the boxA calendar cell.
6A clock hour hand names the hour
The short hand points near an hour number. That is the hour-name. The long hand is not the hour-name.
Reading the long hand as the hour is a miss at this class.
Figure. At 3 o'clock the short hand points at 3 and names the hour. The long hand points at 12 and does not name the hour. No circular rim is drawn.
How it works
- Find the short handHour hand.
- See which number it is at or just pastThat hour.
- Leave minutes for a later fine readHour-name first.
7The poem names the blunder; the table stores the months
A rhyme can remind you a month was skipped. The table of twelve names is the store you trust.
Do not replace the table with only a poem if the poem forgets a month.
Figure. A rhyme can flag a skipped month. The twelve-name table is the store you correct from. Do not trust a poem that forgets July.
How it works
- Hear the blunderA skipped month.
- Check the twelve-name tableThe store.
- Correct from the tablePoem is a hint.
8A sequence of a year is not yet elapsed-time arithmetic
Listing January to December is an order. It is not yet “how many hours from 9 to 2”. That finer elapsed-time can wait.
Do not pretend a month-list answers a clock-duration.
Figure. Listing January to December answers what comes next. It does not answer how many hours from 9 to 2. That is a different tool.
How it works
- Use the year-sequence for month orderWhat comes next.
- Use the week-cycle for weekdaysSeven names.
- Do not force hour-subtraction yetDifferent tool.
Yesterday is
- The calendar box before today
- A duration of three days
- Always Sunday
Yesterday and tomorrow are neighbour boxes.
Notes
- The official chapter title is “Time Goes On”. Teach the school test for that title, not a contest shortcut.
- If a step needs a later class, stop. The next official chapter will pick it up.
Formulas
- 12 months in order, then the year repeats.
- 7 weekday names, then the week repeats.
Reference tables
A missing month breaks the year-cycle. Use the full list.
| # | Month |
|---|---|
| 1 | January |
| 2 | February |
| 6 | June |
| 7 | July |
| 8 | August |
| 12 | December |
Recap
Hold these pegs from the official chapter “Time Goes On”. The wording is ExamMaster’s teaching, not a textbook recap.
- A calendar missing July is a broken month-cycle
- The year-cycle needs every month in order.
- Months have an order that repeats each year
- After December comes January again. That repeat is a new year, not a new month-name invented.
- Days of the week repeat every seven
- After Sunday comes Monday again. Seven names, then the cycle.
- Yesterday and tomorrow sit on the calendar
- Yesterday is the box before today. Tomorrow is the box after. They are neighbours, not feelings.
- Duration is how long, not what date
- “Three days” is a duration. “12 March” is a date. Do not mix them in one sentence without saying which you mean.
- A clock hour hand names the hour
- The short hand points near an hour number.
Practise Time Goes On
Reading is free and needs no account. Practice, mocks and progress live in the app.
- A 4-question practice set that ends the chapter
- 1 quick check with worked explanations
- Timed mocks scored with the real marking scheme
- Readiness tracked per topic, kept on your device