Mentally Calculate the Number of Days in a Month

This video will show you methods to find the number of days in a month as well as to calculate if any year is a Leap year.

Weekly, viral Math puzzles, problems and tricks with answers and explanations for kids and adults alike

References:

Script:
Hi Guys and welcome to another Math Tips and Tricks video.
I was traveling in a bus today without my phone and began to think. How many days to Christmas?
Well today was the 16th of October. There was one full month in between, November, and then December of course.
But I was not sure… Not sure because I was not sure about the number of months in October and November.
Did October have 30 days or 31…. And November….
So in todays video we will look at an easy method to determine the number of days in the month.
And we will also tackle that mysterious month February. How many days does it have?
Ok, lets get cracking then, shall we.
I want you to put your fists together like this, side by side with your knuckles on top.
We are not concerned about the knuckles of our thumbs.
So these here are hills and these here are valleys.
Now I am going to start associating months of the year with my hills and valleys, starting from the left.
This hill is January, this valley is February and so on, till December.
So we are left hilly months and valley months.
Now here is the trick. I will associate 31 with the hilly months
And with the valley months, I will associate 30, except for February of course which is a bit mysterious and could have 28 or 29 days.
But that’s for later….
Ok, lets get back to my problem. How many days till Christmas
As I said earlier, today is the 16th of October.
So lets me use of your new found knowledge
I have 15 more days till then end of October, then 30 more days in November and finally 24 days in December .
That gives me 69 more days till Christmas..
Ok, now let us tackle our next problem. February. How many days does it have?
But wait, lets take a step back here.
Most countries in the world use the Gregorian calendar.
Some countries however do not. Saudi Arabia for example uses the Islamic Calendar , Iran and Afghanistan also use the Persian Calendar.
We will focus on the Gregorian Calendar since the leap year is associated with this calendar.
In the Gregorian calendar, we have two types of years. The Common year and the Leap year.
The common year has 365 days but the Leap year has 366.
So which month is responsible for accommodating this extra day. Well its February as we all know.
So February can have 28 or 29 days depending on whether our year is a common OR Leap year.
And how do we determine this?
So here is the method guys. It may appear a bit tricky at first but keep practicing and it will be easy to understand.
I will use some examples to demonstrate the logic
Lets assume that we have 4 dates as follows:
1900, 2000, 2015 and 2016
We need to find out if they are leap years.
The First thing we need to check is whether our dates are Evenly divisible by 4.
Lets take 1900 first and divide it by 4. 1900 is evenly divisible by 4 that is there is no remainder.
2000 and 2016 are also evenly divisible by 4.
2015 is NOT evenly divisible by 4. So we can quickly say it is NOT a leap year.
Now we are left with three years, 1900, 2000 and 2016.
The next question we need to ask if whether our year is evenly divisible by 100.
Both 1900 and 2000 are divisible by 100. 2016 is NOT.
Now note this carefully.
2016 is divisible by 4 but not 100 so 2016 IS a leap year.
Now we are left with 1900 and 2000.
Both these numbers are divisible by 4 and 100
We need one more test.
Are they divisible by 400?
Lets check.
2000 is divisible by 400 but 1900 is NOT.
So 2000 is a leap year but 1900 is NOT.
And finally I am going to leave you with the logic for calculating the Leap here.

[reginajohnson]

So you have to divide ➗ 4 100 and 400 to the year right if im correct 💯 thank you for sharing this information