This is a brilliant method that uses your hands to multiply numbers. All you need to know is your basic multiplication tables from 1-5 and this works perfectly every time. Make sure subtitles are turned on.
This also works for numbers up to 15. Start with 100, then do everything in the video the same but instead of multiplying your DOWN fingers, multiply your UP fingers.
For example: 7×7 would be the same hand position as 12×12 = 100 + (20+20) + (2×2) = 100 + 40 + 4 = 144.
Source by sunnyskyz