Page 129 - Maths Class 04

You know that February has 28 days every year, but 29 days in every leap
year. Why are there 29 days in February every fourth year ?

The earth revolves around the sun once in a year which takes 365 and a

1
quarter ( ) days.
4
An ordinary year is taken as 365 days only.

1 1 1 1
Four quarters are put together ( + + + = 1) to make an extra day
4 4 4 4
every fourth years.

This is added to the leap year, so there are 366 days in a leap year.
Date Format

Dates are expressed in DD/MM/YYYY format.

Example : 12th June, 2018 is expressed as 12/06/2019.
Time Duration in Days

While calculating days, sometimes we need to include the last day in our

calculation and sometimes we do not.

Here are few examples :

Example : Mohit takes 19 days leave from office. If the last working day is

26th September, on what date does he have to join the office ?

Solution : Mohit was not on leave on 26th, so it is not a part of 19 days leave.

Number of leaves fall in the month of September = 30 – 26 = 4
days.

Number of days of leave in October will be 19 – 4 = 15 days

Mohit has to join office on 16th October.

Example : How many days are there from 8th January to 23rd March, if it is
not a leap year ? (include both dates)

Solution : Days in January = 31 – 7 = 24 days

Days in February = 28 days

Days in March = 23 days

Total Number of days = 24 + 28 + 23 = 75 days

There are 75 days.

Mathematics-4 129