Addition and Subtraction:  Definition, Notation, and Terminology
Channel: Steven Gubkin
Date: 2021-01-06

Course plan:
https://docs.google.com/document/d/1VDKtruAu5nYWw4qDN-etB6cgTmntJzJ_IJwKd_fKYLc/edit?usp=sharing

PDF of notes:
https://drive.google.com/file/d/1PeUt46xeTxzLonssIb6o0D0LuO6zda-x/view?usp=sharing

We define addition and subtraction:

1.  If we combine A units and B units, then we have A+B units all together.  The unit amounts must be the same for all three expressions (for example 3 lbs+ 2lbs  = 5 lbs, but 3 lbs + 2 oz does not equal 5 of anything).  A and B are called terms, addends, or summands.  A+B is called the sum or total.

2.  If we have B units then we need A-B more units to have A units all together.  The unit amounts must be the same for all three expressions.  A is called the minuend, B is called the subtrahend, and A-B is called the difference.