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Chapter 12: Racing Seconds

A 100-metre runner finishes in just 10 seconds. A meal cooks in 20 minutes. A train ride takes 6 hours. Time has many sizes , seconds, minutes, hours, days. Each one helps us in a different situation.

In this chapter we learn to read clocks, convert between time units, add and subtract time, and read the 24-hour format used in railway and airline timetables. By the end, you will be a master of every clock.

What's inside

  • Seconds, minutes, hours and their relations.
  • Reading clocks , analog and digital.
  • The 24-hour format.
  • Time problems , duration and difference.

How to read this chapter

Read in order. Keep an analog clock or a digital watch nearby. The hands-on tasks involve timing yourself doing small things , they make time feel real.

Sub-topics

3 pages
01
Seconds, minutes and hours
Converting between the three main time units.
02
Reading clocks
Reading analog and digital clocks and the 24-hour format.
03
Time duration problems
Finding the duration between two times , useful for journeys and schedules.

Practice quiz

Answer the questions; explanations appear after each.

Quiz
Chapter 12 : Mixed practice
8 questions · pick the best answer
Q1

60 seconds = ? minute

Q2

1 hour = ? minutes

Q3

2 hours 30 minutes = ? minutes

Q4

A race lasts 1 min 45 s. In seconds?

Q5

From 9:15 to 10:00 is:

Q6

Long hand at 12 and short hand at 4 shows:

Q7

If a movie starts at 6:30 PM and lasts 2 h 15 min, it ends at:

Q8

A clock loses 5 minutes every hour. After 4 hours it is behind by: