With this mental math trick you will beable to add and subtract in your head rapidly - a critical skill in everyday math. In this video we look at tips on how to do basic addition and subtraction instantly without using a calculator. Fast math is good math!
To donate to the tecmath channel:https://paypal.me/tecmath
To support tecmath on Patreon: https://www.patreon.com/tecmath
To buy tecmath mechandise: https://teespring.com/stores/tecmath-store