Formal algorithms for subtraction Pencil and paper algorithms in today's mathematics curriculum Two algorithms for subtraction Decomposition (also called renaming ) Equal additions Teaching subtraction algorithms Systematic errors in written subtraction   Informal methods of subtraction General principles of informal computation Informal methods for subtraction Complementary Addition Subtraction in stages Rounding Equal additions principle Renaming principle Other methods More examples of mental computation   References   Back to the Whole Numbers Main Menu