Easy Multiplication Trick you will Actually Use

This multiplication trick is so easy - but you probably don't know it...because it doesn't get taught. That's OK - youtube and tecmath has your back - with this, the easiest multiplication trick you were EVER taught in school! Here is THE mental multiplication lesson playlist - progressing you through your mental multiplication. https://www.youtube.com/playlist?list=PLjbxBzUM6SLk4VGcPW1Jz2tZdaZ6YZEKa To donate to the tecmath channel:https://paypal.me/tecmath To support tecmath on Patreon: https://www.patreon.com/tecmath To buy tecmath mechandise: teespring.com/stores/tecmath-store