Awesome SHORT mental multiplication trick #shorts

#shorts
Can you solve this question in under 2 seconds?
I've got less than a minute to explain it to you!

Here is this trick extended - well worth watching!
https://youtu.be/VcVcKta8OfI

Here is THE mental multiplication lesson playlist - progressing you through your mental multiplication.
https://www.youtube.com/playli....st?list=PLjbxBzUM6SL

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