NCERT Solutions for Class 4 Maths Mela Chapter 12 Ticking Clocks and Calendar

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Let Us Do

Question 1. Notice the number of days in February in the years 2024 and 2025.
Answer: In 2024, February has 29 days. In 2025, February has 28 days. The year 2024 is a leap year, which means it has one extra day added to February.
In simple words: 2024 has 29 days in February because it is a leap year. 2025 has 28 days in February like a normal year.

Exam Tip: Leap years happen every 4 years, and you can identify them by checking if the year number divides evenly by 4. Students should memorize which recent years were leap years.

Question 2. Fill in the blanks with consecutive leap years before and after 2024.
Answer: Leap years happen every 4 years. So the leap years surrounding 2024 are: 2016, 2020, 2024, 2028, 2032, 2036.
In simple words: Leap years come every 4 years. If you add or subtract 4 from any leap year, you get another leap year.

Exam Tip: Always remember the 4-year rule for leap years. Starting from any known leap year, add or subtract 4 to find others quickly.

Question 3. We know that most years have 365 days. How many days would a leap year have?
Answer: A leap year contains 366 days. This happens because an extra day gets added to the month of February, making it 29 days instead of the usual 28.
In simple words: Leap years have one more day than regular years - they have 366 days instead of 365.

Exam Tip: The extra day in a leap year always goes to February. Know the difference between a regular year (365 days) and a leap year (366 days).

Question 4. Write the names of the months when you celebrate your favourite festivals.
Answer:

Exam Tip: Students should know at least 4-5 major festivals and their months. This shows knowledge of cultural awareness and calendar understanding.

Question 5. Answer the following questions by writing the appropriate days of the week:
(a) Today: __________
(b) Yesterday: __________
(c) Tomorrow: __________
(d) Day after tomorrow: __________
(e) Day before yesterday: __________
Answer:
(a) Today: Saturday
(b) Yesterday: Friday
(c) Tomorrow: Sunday
(d) Day after tomorrow: Monday
(e) Day before yesterday: Thursday
In simple words: If today is Saturday, you can count backward to find yesterday and forward to find tomorrow and the day after.

Exam Tip: Practice counting days forward and backward from any starting day. Knowing the order of days of the week is important for this skill.

Question 6. July 1 is a Monday. Write the dates for the next two Mondays.
Answer: Since days of the week repeat every 7 days, the next Monday after July 1 would be July 8 (1 + 7). The Monday after that would be July 15 (8 + 7).
In simple words: Mondays come every 7 days. So if July 1 is Monday, add 7 to get the next Monday, which is July 8, and then July 15.

Exam Tip: Remember that the same day of the week repeats every 7 days. Always add 7 to the date to find the next occurrence of the same weekday.

Question 7. Laali is born on 04/07/2014 and Chotu is born on 04/12/2019. Who is older among the two and how much?
Answer: Laali is the older of the two. She was born in 2014 while Chotu was born in 2019, giving Laali a head start of several years. Year Difference = 2019 - 2014 = 5 years. Month Difference = 12 - 7 = 5 months. Therefore, Laali is older by exactly 5 years and 5 months. Since Laali was born on 04/07/2014, she will turn 5 years old on July 4, 2019. Since Chotu was born on 04/12/2019, his 10th birthday will be celebrated on December 4, 2029.
In simple words: To find who is older, look at the birth years first. Laali was born 5 years before Chotu, so she is older by 5 years and 5 months.

Exam Tip: When comparing ages, always subtract the younger person's birth year from the older person's birth year. Then check the months to be more precise.

Question 8. Check the manufacturing and expiry dates on the wrapper of any biscuit packet.
Answer: I checked a biscuit packet at home. Manufacturing date: 1 January 2025. Expiry date: 1 July 2025. Today's date: 1 March 2025.

(a) How old is the packet of the biscuits?
From 1 January to 1 March = 2 months. So, the answer is: 2 months 0 days.

(b) How many more days are the biscuits safe to eat?
From 1 March to 1 July = 4 months. So the answer is: 4 months 0 days.
In simple words: Check the date it was made and when it goes bad. Count the months between these dates to find the age and how much time is left to use it.

Exam Tip: Always read the manufacturing and expiry dates on food packets. Never use food after the expiry date, as it may not be safe.

Question 9. Notice the day on which July 15 falls in your calendar. Now find out what day is August 15? September 15? October 15? What pattern do you notice?
Answer: I checked my calendar. July 15 is on Monday. August 15 is on Thursday. September 15 is on Sunday. October 15 is on Tuesday. The pattern I noticed: The day moves forward every month. If the month has 31 days, the day moves 3 days ahead. If the month has 30 days, the day moves 2 days ahead. For my own challenge, I chose 10th August. 10th August is on Saturday. So I guessed that 10th September will be on Tuesday. I asked my friends to guess first and then we checked the calendar together.
In simple words: When you look at the same date in different months, the day of the week changes. Months with more days cause the day to jump ahead more.

Exam Tip: Understanding the pattern of how days shift across months helps predict days without always looking at a calendar. This skill is useful for math competitions.

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Let Us Explore

Question 1. With the help of your parents and teachers, explore the names of the months in the Hindu/Islamic/Sikh or any other calendar of your community. Find out when the year begins in each of these calendars.
Answer: I talked to my parents and teacher and learned about different community calendars. In the Hindu calendar, the year usually begins in the month of Chaitra, which comes around March-April in the English calendar. The Islamic calendar begins with the month of Muharram. The Sikh calendar starts with Chet, which falls around March-April.
In simple words: Different communities have their own calendars. The Hindu, Islamic, and Sikh calendars all start their new year at different times than the English calendar does.

Exam Tip: Learning about different community calendars shows respect for diverse cultures. Know at least one calendar system other than the English one.

Question 2. Check how the names of the months in these calendars correspond to the months in the English calendar.
Answer:

Exam Tip: Memorize the order of Hindu months and which English months they overlap with. This helps solve comparison questions on cultural calendars.

Question 3. Identify the months from the Hindu/Islamic/Sikh or any other calendar in which some of the important festivals of the community fall.
Answer: Important festivals and their months in the Hindu calendar:
Diwali - Kartik
Holi - Phalguna
Janmashtami - Bhadrapada
Ram Navami - Chaitra
Makar Sankranti - Paush
In simple words: Each major festival happens during a specific month in the Hindu calendar. Knowing these helps us understand the cultural calendar better.

Exam Tip: Students should know at least 3-4 festivals and their Hindu months. This shows cultural knowledge and calendar understanding together.

Question 4. Identify the dates of the new moon and full moon in your community's calendar every month. Do you notice any pattern?
Answer: New moon and full moon dates show a clear pattern. The new moon comes once every month. The full moon also comes once every month. The pattern I noticed is that the new moon and full moon come after about 15 days of each other every month. This pattern repeats every month throughout the year.
In simple words: The moon goes through changes every month. New moon and full moon happen about 15 days apart, and this cycle keeps repeating.

Exam Tip: Understanding moon cycles helps with understanding lunar calendars used by many communities. The 15-day gap between new and full moon is the key pattern to remember.

Question 5. How are the full moon or new moon days named in your community's calendar?
Answer: In the Hindu community's calendar, the new moon day is called Amavasya. The full moon day is called Purnima. These special days are important for many festivals and celebrations in the community. Different communities might have different names for these days, but they all recognize the new moon and full moon as significant times.
In simple words: The new moon day is called Amavasya and the full moon day is called Purnima. These names come from the Hindu calendar tradition.

Exam Tip: Remember the Sanskrit names Amavasya (new moon) and Purnima (full moon). These terms appear frequently in questions about cultural calendars.

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How many hours in a day?

Question. Look at the picture below. It shows the time spent on different activities by a doctor. Write the number of hours spent on each activity in the space provided. Then, find the total number of hours between 6 o'clock morning to 6 o'clock evening and 6 o'clock morning of the next day. The total number of hours is __________.
Answer:
Waking up to cooking and getting ready: 6:00 AM to 8:00 AM = 2 hours
Travel to hospital: 8:00 AM to 9:00 AM = 1 hour
Staying at hospital: 9:00 AM to 4:00 PM = 7 hours
Travel home: 4:00 PM to 5:00 PM = 1 hour
Resting time: 5:00 PM to 6:00 PM = 1 hour
Cooking: 6:00 PM to 7:00 PM = 1 hour
Time with children: 7:00 PM to 8:00 PM = 1 hour
Dinner and TV: 8:00 PM to 10:00 PM = 2 hours
Sleep: 10:00 PM to 6:00 AM = 8 hours
The total number of hours is 24 hours.
In simple words: A day has 24 hours. When you add up all the time the doctor spent on different activities, the total comes to 24 hours.

Exam Tip: Always remember that 1 day = 24 hours. When solving time problems, make sure all the activities you add up equal 24 hours.

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Fill in the blanks by writing time in the appropriate format.

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Hours and Minutes

Question. Raghav brings milk from the market every morning. Raghav leaves home at 8:20 AM and returns back at 8:35 AM. How much time has he taken?
Answer: Raghav leaves home at 8:20 AM and returns back home at 8:35 AM. Time Taken = 8:35 - 8:20 = 15 minutes.
In simple words: To find how much time passed, subtract the start time from the end time. The time from 8:20 AM to 8:35 AM is 15 minutes.

Exam Tip: When both times are in the morning or both are in the afternoon, simple subtraction works. Always make sure to subtract the earlier time from the later time.

Let Us Do

Question 1. Show the appropriate times on the clock as per instructions.
(a) Raghav started doing his homework at 10:20 AM. He took 25 minutes to finish it. Show the time that he finished his homework.
Answer: Raghav started his homework at 10:20 AM. He took 25 minutes to finish it. The time when he finished his homework = 10:20 + 25 minutes = 10:45 AM.
In simple words: Add 25 minutes to the start time of 10:20 AM to get 10:45 AM as the finish time.

Exam Tip: When adding minutes to a time, if the minutes add up to 60 or more, you need to convert the extra minutes to hours and add them to the hour value.

Question 1. (b) Muneera starts reading a story at 4:15 PM. She finishes reading it in 45 minutes. Show the time that she finished reading the story.
Answer: Muneera starts reading at 4:15 PM. She takes 45 minutes to finish reading. The time when she finished reading the story = 4:15 + 45 minutes = 5:00 PM.
In simple words: Add 45 minutes to 4:15 PM. Since 15 + 45 = 60 minutes, that equals 1 hour, so the answer is 5:00 PM.

Exam Tip: When minutes add up to exactly 60, convert them to 1 hour and add it to the hour part of the time.

Question 1. (c) Akira leaves for school at 8:00 AM. She reaches school in 15 minutes. Observe the shaded portions to fill in the schedule.
Answer: Akira's schedule: Starts for school at 8:00 AM. Reaches school at 8:15 AM (after 15 minutes). Finishes school assembly at 8:30 AM (after 15 more minutes). Dance practice ends at 8:50 AM (after 20 more minutes). Break ends at 9:00 AM (after 10 more minutes).
In simple words: By adding time intervals one after another, you can track each activity and know when each one ends.

Exam Tip: Keep track of the running time as you move from one activity to the next. Add each time interval to the previous end time.

Question. Who do you think is correct? Is there any relation between 1 hour and 60 minutes?
Answer: Both approaches are correct. From 8:00 AM to 9:00 AM is 1 hour, and 1 hour equals 60 minutes. So when someone says one hour, it means the same as saying 60 minutes. The relation is: 1 hour = 60 minutes. Both statements mean the same amount of time, just expressed in different ways.
In simple words: An hour and 60 minutes are the same amount of time. You can use either measurement - they give you the same answer.

Exam Tip: Always remember that 1 hour = 60 minutes. This conversion is essential for solving time problems where you need to switch between hours and minutes.

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Observe the shaded portions:

Question. Observe the clocks and times shown. Use the shaded portions to understand the relationship between hours and minutes.
Answer:
One hour (1 hour) = 60 minutes
Half hour = 30 minutes
Quarter (1/4) of an hour = 15 minutes
Three Quarters (3/4) of an hour = 45 minutes
In simple words: When you divide an hour into parts, half of it is 30 minutes, a quarter is 15 minutes, and three-quarters is 45 minutes.

Exam Tip: Memorize these time fractions: half hour = 30 min, quarter hour = 15 min, three-quarters hour = 45 min. These come up frequently in time problems.

Question. Find out how much time you take to:
(a) Boil milk
(b) Fill water from tap in a bucket
Answer:
(a) It takes about 5 to 10 minutes to boil milk on a gas stove.
(b) It takes about 3 to 5 minutes to fill a bucket with water from a tap.
In simple words: Different everyday tasks take different amounts of time. Boiling milk usually takes longer than filling a bucket with water.

Exam Tip: Estimate the time for common household activities. This helps build a sense of time measurement in real life.

Question. What activities can you do in 5 minutes?
Answer: Many activities can be finished in 5 minutes:
Brush your teeth
Drink a glass of milk or water
Pack your school bag
Read one or two pages of a book
Arrange your study table
Tie your shoelaces and get ready
Water a few plants
Wash your hands and face
In simple words: Five minutes is enough time for quick, everyday tasks. It helps you understand how much you can do in a short time period.

Exam Tip: Knowing how long common tasks take helps you plan your day better. Students who can estimate time well manage their schedules better.

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Let Us Check

Question. Three friends read time from a clock. Who is right? Discuss the error and explain how one reads the clock correctly.
Answer:
First clock: Raghu reads 12:04. Raghav reads 12:20. Rani reads 04:00. The correct reading would be 04:00, so Rani is right.

Second clock: Raghu reads 07:07. Raghav reads 07:25. Rani reads 05:35. The correct reading would be 05:35, so Rani is right.

Third clock: Raghu reads 03:07. Raghav reads 03:35. Rani reads 07:15. The correct reading would be 07:15, so Rani is right.

To read a clock correctly, follow these steps:
- Look at the short hand first - It tells you the hour.
- Look at the long hand next - It tells you the minutes.
- Count the minutes in steps of 5 (5, 10, 15, 20, 25...).
In simple words: The short hand shows hours and the long hand shows minutes. Count the minute marks by fives. Always check where both hands are pointing.

Exam Tip: Many students confuse the short and long hands. Practice identifying which hand is which and what each one represents before reading the time.