Want to knowhow to multiply some big numbers almost instantly in your head?

This trick is a great addition to add to your mental math toolbox.

Here is THE mental multiplication lesson playlist - progressing you through your mental multiplication.
   • Tecmath's mental multiplication lesso...  

To donate to the tecmath channel:https://paypal.me/tecmath

To support tecmath on Patreon:   / tecmath  

To buy tecmath mechandise: https://teespring.com/stores/tecmath-...