Editing Location arithmetic (section)

==== Subtraction ====

Subtraction is also intuitive, but may require expanding abbreviated forms to extended forms to perform [[Carry (arithmetic)|borrows]].

Write the [[Subtraction|minuend]] (the largest number you want to diminish) and remove from it all the digits appearing in the [[Subtraction|subtrahend]] (the smallest number). In case the digit to be removed does not appear in the minuend, then ''borrow'' it by expanding the unit just larger. Repeat until all the digit of the subtrahend have been removed.

A few examples show it is simpler than it sounds :

* Subtract 5 = '''ac''' from 77 = '''acdg''' :
: '''acdg''' - '''ac''' = '''<s>ac</s>dg''' = '''dg''' = 8+64 = 72. 
 
* Subtract 3 = '''ab''' from 77 = '''acdg''' :
: '''acdg''' - '''ab''' = '''abbdg''' - '''ab''' = '''<s>ab</s>bdg''' = '''bdg''' = 2+8+64 = 74.

* Subtract 7 = '''abc''' from 77 = '''acdg''' :
: '''acdg''' - '''abc''' = '''abbccg''' - '''abc''' = '''<s>ab</s>b<s>c</s>cg''' = '''bcg''' = 2+4+64 = 70.