11-Plus Mathematics: Understanding Time

Understanding Time in 11-Plus Mathematics The topic of time is essential in 11-plus mathematics, encompassing various skills such as reading clocks, calculating...

Understanding Time in 11-Plus Mathematics

The topic of time is essential in 11-plus mathematics, encompassing various skills such as reading clocks, calculating time intervals, and solving practical problems related to schedules and timetables.

Reading Clocks

Students must be able to read both analogue and digital clocks. An analogue clock has a face with numbers and hands that indicate the time, while a digital clock displays time in numerical format.

Analogue Clocks: Understand the positions of the hour and minute hands. For example, if the hour hand is on 3 and the minute hand is on 12, the time is 3:00.
Digital Clocks: Recognize time displayed in hours and minutes, such as 14:30 for 2:30 PM.

Converting Between 12-Hour and 24-Hour Time

Students should practice converting between 12-hour and 24-hour formats. This skill is crucial for understanding timetables.

Worked Example

Problem: Convert 3:45 PM to 24-hour time.

Solution:

Since 3:45 PM is in the afternoon, add 12 to the hour: 3 + 12 = 15.
The 24-hour time is 15:45.

Calculating Time Intervals and Durations

Calculating the duration between two times is a common task. Students should learn to subtract start times from end times.

Worked Example

Problem: If a movie starts at 6:15 PM and ends at 8:00 PM, how long is the movie?

Solution:

Convert both times to minutes: 6:15 PM = 18:15 = 18 * 60 + 15 = 1095 minutes.
8:00 PM = 20:00 = 20 * 60 = 1200 minutes.
Duration = 1200 - 1095 = 105 minutes.

Solving Problems Involving Timetables and Schedules

Students will encounter problems that require them to interpret timetables, such as train or bus schedules. They should be able to determine arrival and departure times.

Worked Example

Problem: A train departs at 14:30 and arrives at 15:45. How long is the journey?

Solution:

Convert both times to minutes: 14:30 = 870 minutes, 15:45 = 945 minutes.
Journey duration = 945 - 870 = 75 minutes.

Working with Time Zones

Understanding time zones is also important, especially when dealing with international schedules. Students should know how to adjust times based on different time zones.

For example, if it is 3:00 PM in London (GMT), it is 10:00 AM in New York (EST).

Mastering these concepts will greatly enhance a student's ability to handle time-related problems in the 11-plus mathematics exam.