Society & Culture Helpful and creative trivia

[X_box_X]

What are some not so well known helpful hints and tips that you often use that may not be well known?

Sure, there's always Google to help you find an answer you're looking for, but that may not always be the quickest way to get the answer you're searching for.

Two of my favourite examples I use quite often allows me to always know when a leap year is, and whether you need to adjust your clock forward or back when day light savings comes around.

A leap year, if divided by four, will always give you an answer with a whole number. Similarly, a leap year (for the time being, at least) will occur in the same year as the Summer Olympics.

I.e. 1950 was not a leap year, because if you divide that by four, your answer is 487.5. You therefore know that 1948 and 1952 were leap years because, when divided those years by four, you get a whole number as your answer (487 and 488 respectively).

For daylight savings, in Australia, your clocks are adjusted every Spring and Autumn.

I know that clocks are adjusted forward in Spring, because you can spring forward. You cannot spring back. Similarly, in the Autumn (or the Fall, as they call it in the USA), you wind your clock back. It's more common to fall back than it is to fall forward.

 

[Spongebob]

An oddity of leap years is that not every century, although divisible by 4, is a leap year.

It must be divisible by 400.

So, 2000 was a leap year, but 2100 will not be.

 

[X_box_X]

An oddity of leap years is that not every century, although divisible by 4, is a leap year.

It must be divisible by 400.

So, 2000 was a leap year, but 2100 will not be.

I actually did not know this.

I did a bit of research and found this:

 

[Doss]

I actually did not know this.

I did a bit of research and found this:

View attachment 581108

That's very interesting. When was the last time we were 'meant' to have a leap year but didn't?

 

[X_box_X]

That's very interesting. When was the last time we were 'meant' to have a leap year but didn't?

 

[Frank Bunn]

An oddity of leap years is that not every century, although divisible by 4, is a leap year.

It must be divisible by 400.

So, 2000 was a leap year, but 2100 will not be.

I want to know some trivia. What % of people alive today will make it to see that happen on 28 February/1 March 2100?

 

[raskolnikov]

I want to know some trivia. What % of people alive today will make it to see that happen on 28 February/1 March 2100?

Me. I'll only be 132 years old.

 

[Richard Cranium]

For daylight savings, in Australia, your clocks are adjusted every Spring and Autumn.

I know that clocks are adjusted forward in Spring, because you can spring forward. You cannot spring back. Similarly, in the Autumn (or the Fall, as they call it in the USA), you wind your clock back. It's more common to fall back than it is to fall forward.

Whatever works for you, I guess...?

 

[Bunk Moreland]

I actually did not know this.

I did a bit of research and found this:

View attachment 581108

Wow

Who decides this?

 

[DroopStDanny]

The number 9 is the most magical of numbers.

The sum of the digits of any multiple of 9 is always 9.

9×8=72, 7+2=9
9×72=648, 6+4+8=18, 1+8=9.

Take any number of two or more digits, reverse it and subtract one from the other. The result will always be a multiple of 9. (Obviously does not work for repdigits.)

72-27=45, 45÷9=5
27-72=-45, -45÷9=-5

634942-249436=385506, 385506÷9=42834

 

[X_box_X]

Wow

Who decides this?

Pope Gregory XIII decided it in the 16th century.

 

[X_box_X]

If you have a sequence of consecutive numbers, you can work out the sum of those numbers within seconds with the following formula:

Minimum + Maxium = A
(Maximum + 1) / 2 = B

This can be used to add together all numbers from 1 to 25.

Example:

1 + 25 = 26
(25 + 1) / 2 = 13
26 x 13 = 325

Add all numbers together from 1 to 25 and you get 325 as your answer.

Add all the numbers on a roulette table together (1 through to 36).

1 + 36 = 37
(36 + 1) / 2 = 18.5
37 x 18.5 = 666

All the numbers on a roulette table added together equals 666. No wonder they call it the Devil's game.

 

[the_interloper]

Mathematics has no real proper explanation for what zero is as far as I know.

 

[Frank Bunn]

If you have a sequence of consecutive numbers, you can work out the sum of those numbers within seconds with the following formula:

Minimum + Maxium = A
(Maximum + 1) / 2 = B

This can be used to add together all numbers from 1 to 25.

Example:

1 + 25 = 26
(25 + 1) / 2 = 13
26 x 13 = 325

Add all numbers together from 1 to 25 and you get 325 as your answer.

Add all the numbers on a roulette table together (1 through to 36).

1 + 36 = 37
(36 + 1) / 2 = 18.5
37 x 18.5 = 666

All the numbers on a roulette table added together equals 666. No wonder they call it the Devil's game.

37 x 18.5 = 666

LOL

 

[X_box_X]

37 x 18.5 = 666

LOL

It's meant to be maximum multiplied by the mean, obviously.

 

[Frank Bunn]

It's meant to be maximum multiplied by the mean, obviously.

Don't mean to be mean but your formula doesn't work for even numbers

1,2,3,4. Sum is 10.

1 + 4 = 5
(4+1)/2 = 2.5

5 x 2.5 = 12.5.

 

[X_box_X]

Don't mean to be mean but your formula doesn't work for even numbers

1,2,3,4. Sum is 10.

1 + 4 = 5
(4+1)/2 = 2.5

5 x 2.5 = 12.5.

Again, it's meant to be maximum multiplied by mean.

The maximum in 1, 2, 3, 4 is 4, not 5.

The correct equation is therefore 4 x 2.5 = 10.

The maximum + minimum (5) is needed to get the mean (by dividing it by 2). I.e. 5/2 = 2.5.

 

[RedmanWasHere]

Each square number goes up by each odd number.

1 (+1.)
4 (+3.)
9 (+5.)
16 (+7.)

So on and so forth.