Wednesday, 17 June 2015

Take any four digit number, follow these steps, and you’ll end up with 6174.

1. Choose a four digit number (the only condition is that it has at least two different digits).
2. Arrange the digits of the four digit number in descending then ascending order. 
3. Subtract the smaller number from the bigger one. 

4. Repeat. 
Eventually you’ll end up at 6174, which is known as Kaprekar’s constant. If you then repeat the process you’ll just keep getting 6174 over and over again.

Maths Facts

Here are some interesting maths facts and images courtesy of buzzfeed. Click on the link to see all of them.

A French word for pie chart is “camembert”


The spiral shapes of sunflowers follow a Fibonacci sequence

That’s where you add the two preceding numbers in the sequence to give you the next one. So it starts 1, 1, 2, 3, 5, 8, 13, 21, etc. The Fibonacci sequence shows up in nature a fair bit.

A pizza that has radius “z” and height “a” has volume Pi × z × z × a.

Because the area of a circle is Pi multiplied by the radius squared (which can be written out as Pi × z × z). Then you multiply by the height to get the total volume.

The word hundred is derived from the word “hundrath”, which actually means 120 and not 100



Hundrath is Old Norse.

111,111,111 × 111,111,111 = 12,345,678,987,654,321


It also works for smaller numbers: 111 × 111 = 12321.

In a room of just 23 people there’s a 50% chance that two people have the same birthday.

It’s called the Birthday Problem. In a room of 75 there’s a 99% chance of two people matching.

7 is “arithmetically unique”

It’s the only number below 10 you can’t multiply or divide and keep within group. For example, 5 you can multiply by 2 to get 10 (still within the 1-10 group), 6 and 8 you can divide by 2.

7 also shows up a lot in human culture

We have seven deadly sins, and seven wonders of the world. Not to mention colours of the rainbow, pillars of wisdom, seas, dwarves, days in the week…
This might be because when these things came about there were celestial bodies visible in the sky (the Sun, the Moon, Venus, Mercury, Mars, Jupiter and Saturn).

The number 4 is considered unlucky in much of Asia.


That’s because the words for “four” in Japanese, Cantonese, Mandarin and Korean (shi, sei, si, sa) sound the same as the words in those languages for death.

10! seconds is exactly 6 weeks

10! means 10 factorial. 10! = 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 3628800 seconds. Which is 42 days, or 6 weeks, exactly.

555 is used by some in Thailand as slang for “hahaha”, because the word for “five” is pronounced “ha”







Wednesday, 3 June 2015

The Surprising Places We Waste Energy

'In Joe Hanson’s third episode of It’s Okay to Be Smart’s energy series, he explores the surprising places that we can be more energy efficient: Food waste, water waste, fertilizer waste, food transportation, gasoline consumption for powering cars, planes, trains, or ships… the list goes on.' source

This video not only deals with science and the environment, it also features many opportunities to link with maths - namely fractions, percentages and measurement.