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Time Goes On - Reading a Clock

Grade 3CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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The Clock Face: A clock face is a circular dial numbered from 11 to 1212. Between every two consecutive numbers, there are 55 small divisions, each representing 11 minute. This means there are a total of 12×5=6012 \times 5 = 60 small divisions representing 6060 minutes in a full circle.

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The Hands of a Clock: A clock typically has two main hands. The shorter hand is called the 'Hour Hand' and it shows the hours. The longer hand is called the 'Minute Hand' and it shows the minutes. Some clocks also have a very thin hand that moves quickly called the 'Second Hand'.

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Reading the Hour Hand: If the hour hand is pointing exactly at a number, say 44, and the minute hand is at 1212, the hour is 44. If the hour hand is between two numbers, like 44 and 55, we always take the smaller number as the current hour, which is 44.

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Reading the Minute Hand: To find the number of minutes, we look at the number the long hand is pointing to and multiply it by 55. For example, if the minute hand is at 77, the minutes are 7×5=357 \times 5 = 35 minutes. If the minute hand is at 1212, the minutes are 00.

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Quarter and Half Hours: When the minute hand is at 33, it is called 'Quarter Past' (1515 minutes). When it is at 66, it is called 'Half Past' (3030 minutes). When it is at 99, it is called 'Quarter To' (4545 minutes), meaning 1515 minutes are left to reach the next hour.

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A.M. and P.M.: A day is divided into two parts of 1212 hours each. The time from 1212 midnight to 1212 noon is called 'a.m.' (Ante Meridiem). The time from 1212 noon to 1212 midnight is called 'p.m.' (Post Meridiem).

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Writing Time: Time is written in the format Hours:MinutesHours:Minutes. For example, if the hour is 88 and the minutes are 2020, we write it as 8:208:20.

📐Formulae

1 hour=60 minutes1 \text{ hour} = 60 \text{ minutes}

1 minute=60 seconds1 \text{ minute} = 60 \text{ seconds}

1 day=24 hours1 \text{ day} = 24 \text{ hours}

Minutes=Number on clock×5\text{Minutes} = \text{Number on clock} \times 5

1 week=7 days1 \text{ week} = 7 \text{ days}

💡Examples

Problem 1:

Look at a clock where the hour hand is between 77 and 88, and the minute hand is pointing exactly at 55. What is the time?

Solution:

Step 1: Identify the hour. Since the hour hand is between 77 and 88, the hour is 77. Step 2: Identify the minutes. The minute hand is at 55. Multiply by 55: 5×5=255 \times 5 = 25 minutes. Step 3: Combine them. The time is 7:257:25.

Explanation:

We determine the hour by looking at the last number the hour hand passed and calculate minutes by multiplying the minute hand's position by 55.

Problem 2:

A school bus arrives at 8:108:10 a.m. and takes 3535 minutes to reach the school. At what time does the bus reach the school?

Solution:

Step 1: Start with the arrival time: 88 hours and 1010 minutes. Step 2: Add the travel duration to the minutes: 10 minutes+35 minutes=45 minutes10 \text{ minutes} + 35 \text{ minutes} = 45 \text{ minutes}. Step 3: The hour remains 88. Step 4: The final time is 8:458:45 a.m.

Explanation:

To find the end time, we add the elapsed time (minutes) to the starting minutes. Since the sum is less than 6060, the hour does not change.