Download Racing Seconds – NCERT Class 5 Maths Chapter 12 PDF from the new NCERT Class 5 Maths book Maths Mela (2026-27). Read the chapter online or download the free PDF. A second is a very small piece of time. Say one thousand one out loud — that takes about one second. Blinking your eyes takes less than a second. The thin red hand on a wall clock is the seconds hand. It is the fastest hand: it goes right round the…
Racing Seconds PDF – Chapter 12 of Maths Mela
Read the chapter online or download the PDF.
| Chapter | Download | |
|---|---|---|
| Chapter 12 PDF | Racing Seconds | View PDF |
| Full book | NCERT Class 5 Maths – Maths Mela | View Book |
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What Is in Racing Seconds? (Class 5 Maths Chapter 12)
- A second is a very small piece of time. Say one thousand one out loud — that takes about one second. Blinking your eyes takes less than a second. The thin red hand on a wall clock is the seconds hand. It is the fastest hand: it goes right round the dial in one minute.
- 60 seconds make 1 minute. 60 minutes make 1 hour. This is the one fact the whole chapter rests on. Watch the seconds hand: after it has ticked 60 little marks it has gone once round, and the minute hand has moved on by exactly one mark. So 1 min = 60 s and 1 hr = 60 min.
- Time is counted in sixties, not in tens. In money, 10 tens make 100. In time, it is 60 that makes the next unit. So when seconds add up past 60, we carry 1 to the minutes. 40 s + 35 s = 75 s = 1 min 15 s. And when we cannot subtract, we borrow 1 minute and it becomes 60 seconds, not 10.
- Reading a clock with three hands. Look at the short thick hand first — that is the hour hand; the number it has just passed is the hour. Then the long hand — the minute hand; count in fives, one five for each number after 12. Then the thin hand — the seconds hand; count in fives from 12 again. A clock showing hour hand between 5 and 6, minute hand on 7 and seconds hand on 12 reads 5:35 and 0 seconds.
- The 12-hour way and the 24-hour way. A day has 24 hours, but a clock face has only 12 numbers. So the same 12 numbers are used twice — once for a.m. (midnight to noon) and once for p.m. (noon to midnight). Railway and airline timetables usually do not use a.m. and p.m. They count straight on from 00 to 23. Rule: an a.m. time stays the same; for a p.m. time add 12 to the hour. So 05:30 p.m. = 05:30 + 12:00 = 17:30 hours.
- Changing hours into minutes: multiply by 60. 3 hours = 3 × 60 = 180 minutes. To change minutes back into hours, divide by 60: 180 ÷ 60 = 3 hours. A leftover is written as minutes: 220 ÷ 60 gives 3 with 40 left over, so 220 min = 3 hours 40 minutes.
- Changing minutes into seconds: multiply by 60 again. 5 min = 5 × 60 = 300 seconds. And back the other way, divide by 60: 320 ÷ 60 gives 5 with 20 left over, so 320 s = 5 min 20 s.
- Finding how long something took. Do not start with a subtraction sum. Start at the earlier time and jump forward in easy hops — first whole hours, then the extra minutes. From 08:00 to 09:00 is one hop of 1 hour; from 09:00 to 09:05 is another hop of 5 minutes. Total 1 hour 5 minutes. Adding a duration works the same way, only forwards.
Quick revision – Racing Seconds
| Word | What it means | Where it appears | Example |
|---|---|---|---|
| Second | The smallest unit of time in this chapter; 60 of them make one minute | Pages 156–157, the race timings | Saying ‘one thousand one’ takes about 1 second |
| Minute | 60 seconds | Page 157, 1 min = 60 seconds | The winner took 1 minute 55 seconds |
| Hour | 60 minutes | Page 161, Conversion of Hours to Minutes | Rani painted for 2 hours 10 minutes |
| Seconds hand | The thin, fastest hand of a clock; one full round = 1 minute | Pages 159 and 160 | Red hand pointing at 6 means 30 seconds |
| Minute hand | The long hand; it moves one small mark when the seconds hand goes once round | Pages 155, 159, 160 | Green hand on 9 means 45 minutes |
| Hour hand | The short, thick hand; it tells the hour | Pages 155, 159, 160 | Blue hand between 5 and 6 means the hour is 5 |
| A.m. | The 12 hours from midnight to noon | Page 156, the time-format table | 05:30 a.m. is early morning |
| P.m. | The 12 hours from noon to midnight | Page 156, the time-format table | 09:35 p.m. is night |
| 12-hour format | Time written with a.m. or p.m. | Page 156, left column | 02:30 p.m. |
| 24-hour format | Time counted straight on from 00 to 23 hours, with no a.m. or p.m. | Page 156, right column | 02:30 p.m. = 14:30 hours |
| Time elapsed (duration) | How much time passed between a start time and an end time | Page 155, question 4 | 09:15 a.m. to 11:30 a.m. is 2 hours 15 minutes |
| Double number line | Two number lines drawn one above the other so matching values line up | Pages 161 and 162 | 1 hr above, 60 min below |
| Estimate | A sensible guess made before measuring | Page 157, Let Us Do | Guess how many hops in a minute, then count |
Old NCERT vs New – Class 5 Maths
This chapter is from Maths Mela, the new NCERT Class 5 Maths book (NCF-SE 2023, used from 2025-26). It replaced the old book “Math-Magic”, so chapter numbers and names differ from older PDFs.
Solutions and All Chapters
Answers to the exercises and the full chapter list of Maths Mela:
Racing Seconds – Overview
| Class | Class 5 |
| Subject | Maths |
| Book | Maths Mela – new NCERT book |
| Chapter | 12 of 15 – Racing Seconds |
| Book pages | 155 – 163 |
| Edition | NCERT Reprint 2026-27 |
| Session | 2026-27 |
| Free – read online or download |
Class 5 Maths Chapter 12 – FAQs
Where can I download Racing Seconds Class 5 PDF?
From the download table on this page – the chapter PDF is free, and the full book is linked too.
What is Class 5 Maths Chapter 12 about?
A second is a very small piece of time. Say one thousand one out loud — that takes about one second. Blinking your eyes takes less than a second. The thin red hand on a wall clock is the seconds hand. It is the fastest hand: it goes right round the dial in one minute.
Is Racing Seconds from the new NCERT Class 5 Maths book?
Yes. It is chapter 12 of maths mela, the new NCERT Class 5 Maths book for 2026-27.
Is this the latest NCERT edition for 2026-27?
Yes – the PDF is NCERT’s latest edition for the 2026-27 session.
Where are the NCERT Solutions for Class 5 Maths Chapter 12?
Open the NCERT Solutions link above for answers to the exercise questions.