You probably learned how to do long multiplication by hand in school. Computers used the same algorithm to multiply large numbers together, until computer scientists discovered much, much faster methods, including one published this year that’s “perfect!”
THUNK Discord! - https://discord.gg/YHVjeSk
Mathematicians Discover the Fastest Way to Multiply, by Kevin Hartnett - https://www.quantamagazine.org/mathematicians-discover-the-perfect-way-to-multiply-20190411/
Integer multiplication in time O(n log n) (Harvey & Hoeven, 2019) - https://hal.archives-ouvertes.fr/hal-02070778/document
Polynomial multiplication over finite fields in time O(n log n) (Harvey & Hoeven, 2019) - https://texmacs.org/joris/ffnlogn/ffnlogn.html
David Harveys personal Q&A about the paper - https://web.maths.unsw.edu.au/~davidharvey/research/nlogn/index.html
The Complexity of Computations (Karatsuba, 1995) - http://www.ccas.ru/personal/karatsuba/divcen.pdf
Fast multiplication of large numbers (Schnhage & Strassen, 1971) - https://link.springer.com/article/10.1007%2FBF02242355
Multiplying 41*37 with Fast Fourier Transform by hand - https://www.youtube.com/watch?v=YDhsLhTK3Bs
Mathematicians may have found the fastest way to multiply huge numbers, by Emily Conover - https://www.sciencenews.org/article/mathematicians-may-have-found-fastest-way-multiply-huge-numbers