Quick: Multiply by 11
The Mathemagician reveals the surprisingly easy trick behind instantly multiplying any two-digit number by 11. It’s really as simple as 2 + 2.
Recorded June 2010; Posted October 2010

The Mathemagician reveals the surprisingly easy trick behind instantly multiplying any two-digit number by 11. It’s really as simple as 2 + 2.
Recorded June 2010; Posted October 2010