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Tick-Tick-Tick - Tick-Tick-Tick

Grade 4CBSE

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

🔑Concepts

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Reading Time: The clock face is divided into 1212 large divisions representing hours and 6060 small divisions representing minutes. The hour hand moves from one number to the next in 11 hour, while the minute hand completes one full circle.

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Units of Time: Time is measured in seconds, minutes, hours, days, weeks, months, and years. 11 hour is equal to 6060 minutes, and 11 minute is equal to 6060 seconds.

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12-Hour Clock: This system uses AM (Ante Meridiem) for the time between midnight and 1212 noon, and PM (Post Meridiem) for the time between 1212 noon and midnight.

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24-Hour Clock: Often used by railways and airlines. Time starts from 00:0000:00 (midnight) to 23:5923:59. For PM times, we add 1212 to the 12-hour clock format. For example, 2:002:00 PM is 2+12=14:002 + 12 = 14:00 hours.

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Calculating Duration: To find the duration of an activity, subtract the start time from the finish time. If the minutes to be subtracted are greater, borrow 11 hour as 6060 minutes.

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Calendar and Leap Year: A standard year has 365365 days. A leap year occurs every 44 years and has 366366 days, with February having 2929 days instead of 2828.

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Writing Dates: Dates can be written in formats like DD/MM/YY. For example, 15/08/2315/08/23 represents 15th15^{th} August 20232023.

📐Formulae

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

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

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

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

1 year=12 months=365 days1 \text{ year} = 12 \text{ months} = 365 \text{ days}

Time Duration=End Time−Start Time\text{Time Duration} = \text{End Time} - \text{Start Time}

💡Examples

Problem 1:

Convert 55 hours and 2020 minutes into total minutes.

Solution:

5×60+20=300+20=320 minutes5 \times 60 + 20 = 300 + 20 = 320 \text{ minutes}

Explanation:

Since 11 hour = 6060 minutes, we multiply the number of hours by 6060 and add the remaining minutes.

Problem 2:

A train leaves at 15:3015:30 hours. What is the time in the 12-hour clock system?

Solution:

15:30−12:00=3:30 PM15:30 - 12:00 = 3:30 \text{ PM}

Explanation:

In a 24-hour clock, if the hour is greater than 1212, we subtract 1212 to find the PM time in the 12-hour system.

Problem 3:

Find the duration between 10:1510:15 AM and 12:4512:45 PM.

Solution:

12 h 45 min−10 h 15 min2 h 30 min\begin{array}{r} 12 \text{ h } 45 \text{ min} \\ - 10 \text{ h } 15 \text{ min} \\ \hline 2 \text{ h } 30 \text{ min} \end{array}

Explanation:

Subtract the starting hour and minutes from the ending hour and minutes to find the elapsed time.

Problem 4:

If a school holiday starts on 5th5^{th} May and ends on 20th20^{th} May, how many days long is the holiday?

Solution:

20−5+1=16 days20 - 5 + 1 = 16 \text{ days}

Explanation:

To calculate the number of days between two dates including both start and end dates, we subtract the start date from the end date and add 11.