1st Class Mathematics Calendar Time and Calendar

TIME AND CALENDAR

1.    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 everyday. 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.

•            Example:

Jenifer takes one minute to eat a bread, while Steve takes 4 minutes to eat a bread. Which one is true for both of them?

(a) Jenifer takes more time          

(b) Steve takes less time

(c) Jenifer and Steve take equal time

(d) Jenifer takes less time and Steve takes more time

(e) None of these

Answer (d)

Explanation: Option (d) is correct because [4] minutes taken by Steve is more than [1] minute that is taken by Jenifer.

Time Indicating Watches

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

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 O'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 [3] 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: