Lecture:
Videos: Note, this time I have done each small piece separately, so if you want to go back and re-watch an algorithm, you can watch just one of the videos
Introduction
Universal algorithms for addition: student invented and the expanded algorithm.
Friendly numbers add algorithm
Add algorithms from other countries
Negative numbers algorithm
Left to right subtraction
Round and compensate for subtraction
Trade first subtraction
Equal additions algorithm
Test your understanding: