Commutative law of addition: m + n = n + m . A sum isn’t changed at rearrangement of its addends.

Commutative law of multiplication: m · n = n · m . A product isn’t changed at rearrangement of its factors.

Associative law of addition: ( m + n ) + k = m + ( n + k ) = m + n + k . A sum doesn’t depend on grouping of its addends.

Associative law of multiplication: ( m · n ) · k = m · ( n · k ) = m · n · k . A product doesn’t depend on grouping of its factors.

Distributive law of multiplication over addition: ( m + n ) · k = m · k + n · k . This law expands the rules of operations with brackets (see the previous section).