# National Pi Day

Today marks National Pi Day!

So what exactly is pi? Pi is the name used for the ratio of the circumference of a circle to its diameter - which is a mathematical constant. That means that every circle, no matter how big, will always have the same ratio! Pi is equal to, approximately, 3.14159, although it is a transcendental and irrational number, which means that it continues on forever without any patterns or repetition appearing. Mathematicians have calculated pi to over one trillion digits beyond its decimal point!

To celebrate National Pi Day we have found some useful techniques and tips to help you remember more of pi than just 3.14:

**1) Grouping digits in sets of four**

Write out pi to however many digits you hope to memorise. After you've done this, group the digits into sets of even numbers e.g. (3.141) (5926) (5358) (9793)

It's best to start with a smaller amount of information when trying to memorise a lot of numbers, so begin by memorising four groups of four digits. Once you have these firmly in your memory, focus on the next set.

**2) Grouping digits as telephone numbers**

Most memorisation techniques, known as "mnemonics", follow the idea that it's easier to remember a complex series of digits if they are associated with a pattern or sequence that is more memorable to an individual. If you group the digits for pi so that they follow the pattern of a telephone number, you may find that the sequences are easier remember.

Here's an example - instead of trying to remember 3.1415926535, try remembering it in this pattern instead: 3.1415 926 535.

**3) Write out pi as sentences using pilish**

Pilish is a style of writing wherein the number of letters in each word stands for the corresponding number in pi. One of the earliest examples of this is *"How I need a drink, alcoholic in nature, after the heavy lectures involving quantum mechanics!"* which was written by English physicist Sir James Jeans, and translates into 3.14159265358979.

In 1996, American mathematician Mike Keith wrote a *'Cadaeic Cadenza'*, a short story in which some 3,800 digits of pi were encoded using Pilish. Keith has also published a full-length book called *'Not A Wake'* in Pilish, which currently holds the record of the longest Pilish text with 10,000 digits.

**4) Write out pi as a poem using pilish**

Alternatively, you can use pilish to turn pi into a poem (or *'piem'*, as they are often called). Lots of people find it easier to memorise text that rhymes!

The 1960 book *'Playing With Words'*, written by Joseph Shipley, features the following poem which covers the first 31 digits of pi:

*"But a time I spent wandering in bloomy night;*

*Yon tower, tinkling chimewise, loftily opportune.*

*Out, up, and together came sudden to Sunday rite,*

*The one solemnly off to correct plenilune."*

So how will you celebrate National Pi Day? If you try to memorise the digits of pie, or writing a pilish poem, be sure to let your Instructor know!