1st Class Mathematics Calendar Time and Calendar

                                                                                        Time and Calendar

Concept of Time

A day is divided into hours. An hour is divided into minutes and a minute is divided into seconds. See the following examples:

For example, Leesa reaches school on 8 O'clock every day. Here 8 O'clock is the time

Hours, Minutes and Seconds

Hours, minutes and seconds are units for the measurement of time.

For example, we can say

2 hours; 2 minutes; 2 seconds.

Now just remember:

24 hours  = 1 day

1 hour = 60 minutes

1 minute = 60 seconds

Hence 1 day = 24 hours

Knowing Time

Knowing time means knowing period or duration of a certain event.

For example,

A man goes to a certain distance in 60 minutes. We can therefore say that he takes 1 hour to cover the certain distance.

Time Indicating Watches

Let's see the face of a clock given below:

                         CLOCK

Look carefully at the clock given. It has two hands. One is the shorter hand, which is called hour hand. The other is the longer hand, which is called minute hand.

Important Points

• The hour hand moves from one number to the next in 1 hour.
• The hour hand takes two complete rounds in a day.
• The minute hand takes 1 hour to complete one round.

Reading Time from a Clock

Trick 1

When the minute hand is at 12 then the actual time is the number that is indicated by the shorter or hour hand. For example, just see the following:

Example:

Here the longer or the minute hand is at 12 and hour or shorter hand indicates 9.

Therefore, the time is 9 or 9 0 ' clock.

Similarly, in the clock shown below. The time is 4 or 4 O'clock.

Trick 2

Counting of the movements of minute hand at each of the number starting from 1 to 12 is done in the unit of 5, as given below:

5, 10 , 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60

If shorter or hour hand is somewhere between 2 and 1 and minute hand is at 5 then the time is 2 : 25 and it will be read as ‘25’ minutes past 2.

• Example:

The above clock shows the time ten past five that is 10:05.

Calendar

A calendar is a system of organising various periods of time. This is done by giving names to the periods as days, weeks, months and year.

Week  

A period of seven days is called a week. In other words there are seven days in a week. They are as follows:

Months in a Year

There are 12 months in a year. They are as follows: