3rd Class Mathematics Calendar Time and Calendar

LEARNING OBJECTIVES

This lesson will help you to:—

• understand the concept of time.
• read the clock time to the nearest hour.
• read a calendar to find a particular day and date.

Real life Examples

• Knowledge of time and calendar helps us to form time table in school.
• Keeping a track of time prevents us from getting late for work.
• Knowledge of calendar helps us record important dates like birthdays, anniversaries, holidays, etc.
• Time helps us to organize our tasks so that we can manage them properly.
• Calendar helps in maintaining appointments.
• Clocks help us to set alarms, to wake up in the morning and get ready for school or office.

QUICK CONCEPT REVIEW

1. A clock helps us in knowing time.

In a clock there are three needles or hands- 'hour' hand, 'minute' hand, and "second" hand

The shortest hand is 'hour' hand.

The longest hand is 'minute' hand.

The thinnest hand which is moving very fast which is the "second" hand.

Look at the picture given below:

In order to read the clock, look at the hour hand first and then look at the minute hand.

For example, if the hour hand is at "3" and minute hand is at '12' then the time is 3o'clock.

If the minute hand is at:

‘1’, it means 5 minutes have passed so the time will become 3:05

‘2’, it means 10 minutes have passed so the time will become 3:10

'3', it means 15 minutes have passed so the time will become 3:15

'4', it means 20 minutes have passed so the time will become 3:20

'5', it means 25 minutes have passed so the time will become 3:25

‘6’, it means 30 minutes have passed so the time will become 3:30

'7', it means 35 minutes have passed so the time will become 3:35

'8', it means 40 minutes have passed so the time will become 3:40

'9', it means 45 minutes have passed so the time will become 3:45

'10', it means 50 minutes have passed so the time will become 3:50

'11', it means 55 minutes have passed so the time will become 3:55

Then, again the minute hand comes at '12', now the hour hand will come at '4' so the time will become 4 o'clock.

Now look at the clock in your room and note down the time in your notebook.

2. A calendar helps us to know about days, weeks, months and year.

We read the calendar to tell the days and dates.

Historical Preview

• In previous time, people used to tell time by looking at the sun’s shadow.
• People used to meet at down, when the sun came up, or at noon, when the sun was highest in the sky, or at sunset, when the sun went down.
• The time from one new moon to another was a month, and the time from one spring to the next was a year.

Misconcept / Concept

Misconcept: Interpretation of long hand for ‘hour’ and small hand for ‘minute’

Concept: The longest and helps in determining ‘minutes’ and the shortest hand helps in determining ‘hour’

Misconcept: Interpretation of numbers 1, 2, 3,……, 12 as 1, 2, 3, …….., 12 for determining both hours and minutes.

Concept: People usually write the number 1, 2, 3, ……, 12 as it is for writing minutes which is wrong. In order to determine the minutes passed, multiple the number the ‘minute’ hand is pointing with 5.

In order to read the calendar, look at the date first and then look at the day on which it falls. The month and the year are always mentioned above it.

For example, 15^th November 2012 falls on Thursday.

A date is written in the following ways:

Date/month/year e.g. 15/11/2012

                                Or

Date-month-year e.g. 15-11-2012

                                Or

Date month' year e.g. 15+h November' 2012

Now write your birth date in your notebook using different formats.

Examples:

TIME

1. At what time do you brush your teeth? 6o'clock?
2. At what time do you take bath? 6:30?
3. People cannot carry a clock with them so they wear a watch to keep a track of time.
4. At what time does your family have dinner? 9 o'clock?

5. Do you check the time when you go to bed? 10:30?

CALENDAR

1. Do you remember the date when you wished "Happy New Year' to your friends?

1st January 2013 or 01/01/2013

2. A new baby has born today.

Do you remember the date when you were born?

3. When do your winter holidays start?
4. Do you remember the date when India got independence?
5. 15^th August 1947

READING A CALENDER

READING A CLOCK

SHORTCUT TO PROBLEM SOLVING

1. In order to find the minutes passed, multiply the number 'minute' hand is pointing at with 5. For example, hour hand is at 6 and minute hand is at 3, then multiply 3 with 5 which will make 15 so the time will become, 6:15.
2. The shortest hand in the clock is 'hour' and the longest hand is 'minute' while the thinnest hand is 'second'.