Multiplying 1's from Mathmagical on Vimeo.
Often overlooked when teaching multiplication strategies is ensuring that a student understands the simple things like the “identity”. The number 1 is the “multiplicative identity” for integers, real numbers, and complex numbers. In multiplication, any number multiplied by the “identity” is equal to itself. While this may seem a bit fancy, it’s important to lay the foundation for this understanding in preparation for learning algebraic and trigonometric strategies down the road.
A sample of Multiplying 1’s from Multilplying Time! is embedded above.