Articulates the process and reasoning/validity of using the standard algorithm
-Built from base-ten system
-Minuend subtracted from subtrahend
-When digit in minuend>subtrahend, need to borrow
-Borrowing is renaming a collection of that place value as 10 of the smaller place value
-Reducing the borrowed digit by one notates the exchange
-Increasing the borrowing digit by ten accounts for the base-10 equivalence
-Subtraction can continue
-When a 0 is in the borrowing place, a second exchange is necessary to free up values
-Borrowing across a 0 results in 10, then 9 in the borrowed place and still 10 in the borrowing
-Difference is the subtrahend reduced by the minuend