411 REFERENCE · Wikibooks
Arithmetic Course/Number Operation/Multiplication
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Multiplication
Addition is the operation of adding (combining) two quantities which can be represented by
A x B
Operation
a x b = b x a
a x b x c = a x (b x c) = (a x b) x c
Rules
Any number multiply by zero is equal to zero
a + 0 = a
Any number multiply to itself is
a x a = a2
Any negative number multiply by itself is
(-a) x (-a) = a2
Any number multiply to its negative is
a x (-a) = -a2