Class 5 Maths Chapter 12, Racing Seconds, introduces the second as a unit of time alongside minutes and hours, teaches conversions between 12-hour (a.m./p.m.) and 24-hour clock formats, and calculates elapsed time, starting time and finishing time.
What Class 5 Mathematics Chapter 12 Covers
12-Hour & 24-Hour Clocks and Seconds converts daily schedules and train timings between 12-hour (a.m./p.m.) and 24-hour railway time, and introduces 1 minute = 60 seconds and 1 hour = 60 minutes using stopwatches and 100 m school races.
Elapsed Time & Time Arithmetic uses timeline jumps to find time duration (elapsed time), start time or end time across a.m. and p.m. boundaries, and converts hours into minutes and minutes into seconds.
Exercises in Chapter 12
- Let Us Do, Let Us Think, and Let Us Solve practice exercises.
- Interactive number games, visual grids, and hands-on puzzles.
Read Class 5 Mathematics Chapter 12 Online
More Chapters
- Previous: Chapter 11: Grandmother’s Quilt
- Next: Chapter 13: Animal Jumps
- Hindi medium: Class 5 Maths Chapter 12 PDF in Hindi (Ganit Mela)
- All Mathematics chapters and the other Class 5 books: Class 5 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
- Every book chapter by chapter: NCERT chapter wise PDF
FAQ
How do you convert p.m. times into the 24-hour clock format?
For times from 1:00 p.m. to 11:59 p.m., add 12 to the hours (for example, 02:30 p.m. becomes 14:30 hours, and 08:15 p.m. becomes 20:15 hours).
How many seconds are in 1 minute, and how many minutes are in 1 hour?
There are 60 seconds in 1 minute and 60 minutes in 1 hour (which equals 3,600 seconds in 1 hour).