Pi

The ratio of a circle’s circumference to its width

$\pi \approx 3.14159265358979$

$\frac{1}{\pi }=\frac{2\sqrt{2}}{99^2}\sum _{k=0}^{\infty }\frac{(4k)!}{k{!}^4}\frac{26390k+1103}{396^{4k}}$

• Ramanujan’s series for calculating digits of pi which converges quite fast
• Wikipedia article

Algorithms

• Chudnovsky Algorithm
  • Current fastest algorithm to calculate digits of pi

Mnemonic

3.14 159 26535 897932 846264 3383 27950 288 4197 169 399 37510

• Splitting it this way helps with chunking
• Once memorized 50 digits of pi in ~10 minutes that lasted for at least a day using simple chunking
• Can use other methods such Method of Loci or a personal story to more permanently memorize the digits
• Pi quiz