Holiday Fun #3: It’s (never) too late to learn long multiplication!

Don't worry, you can keep your calculator - but understanding how to speed up multiplication can make you safer online.

from Naked Security - Sophos https://nakedsecurity.sophos.com/2017/12/29/holiday-fun-3-its-never-too-late-to-learn-long-multiplication/
via CCTV Camera Installers