This chapter helps students understand time and its measurement using seconds, minutes, and hours. They learn important conversions such as:
1 minute = 60 seconds
1 hour = 60 minutes = 3,600 seconds
1 day = 24 hours
Students practice calculating elapsed time by finding the difference between start and end times. The chapter also explains the difference between the 12-hour clock (a.m./p.m.) and the 24-hour clock, including special times like midnight (00:00) and noon (12:00).
In race examples, time is converted into seconds to compare results easily. Tools like the double number line help in converting between hours, minutes, and seconds.
Students also learn that in races, less time means faster speed, and more time means slower speed.
Overall, this chapter builds strong skills in reading clocks, converting time units, and calculating time differences accurately.
Key Points
• Time Units
1 min = 60 sec ⏱
1 hr = 60 min = 3,600 sec
1 day = 24 hr
• Elapsed Time (Time Passed)
Subtract start time from end time.
Example: 05:35 a.m. → 05:55 a.m. = 20 min 🧘
• 12-hr vs 24-hr Clock
02:30 p.m. = 14:30
09:35 p.m. = 21:35
Midnight = 00:00, Noon = 12:00
• Race Timing in Seconds
Winner’s time: 1 min 55 sec → 115 sec
Comparing in seconds makes small differences easy to see.
• Double Number Line
Helps convert hours ↔ minutes ↔ seconds.
Example:
1 hr = 60 min = 3,600 sec
2 hr = 120 min = 7,200 sec
• Speedy Thinking
More time taken → slower.
Less time taken → faster.
👉 👉 ⏳ “Every second counts.” Whether in sports, studies, or daily routines, understanding time helps us manage tasks, plan better, and improve speed.