# How Many Indexed Digits of Pi Do You Know?

#### How Many Indexed Digits of Pi Do You Know?

How many indexed digits of pi to you know? Now you can test yourself over here:

You can use this skill to impress people in public -- ask them to look up the correct answer on their phones while you pull answers out of your memory palace. :)

**Edit:** it might help to have some instructions.

What I do is put the digits of pi into small memory palaces of 10 locations each. Each location holds four digits, so there are 40 digits per palace.

I keep the palaces in order by placing a number shape image in front of each one.

The decimal point takes up the space of one digit, so when calculating my position I have to shift everything over one space to the left. My first location holds 3.14: a butterfly (3) dropping a stone (.) on an otter (14).

When I'm given a position, say "the 159th digit of pi", I divide the number by 40 to find out which palace it is in. 40 into 160 is 4, so I know that I'm near the last position of the fourth memory palace. I can find the correct palace by looking for the flag (number shape: 4) which is in front of the fourth memory palace.

159 would be the second to last position of the fourth palace, except that I have move one place farther to account for the decimal point taking up one space. That means the 159th digit is the last digit of memory palace number four, and the 160th digit is the first digit of memory palace number five.

The images in the last location of memory palace #4 are a police dog (17) attacking a werewolf (45). That means the 159th digit of pi is a 5.

The purpose for the script is to increase speed so that I can give a faster answer when people quiz me. :)

Click here to give it a try.