Can we multiply numbers in any order obtaining the same result?

2 Answers
Apr 26, 2018

Yes, their order doesn’t matter you always get the same result.

Explanation:

This is called the commutative property of multiplication. If #a,b# are numbers, then #a xx b = bxxa#.

Apr 28, 2018

Yes, since multiplication is both commutative and associative.

Explanation:

If #a# and #b# are any two (ordinary) numbers then:

#a xx b = b xx a#

This is called the commutative property of multiplication.

If #a#, #b# and #c# are any three (ordinary) numbers then:

#a xx (b xx c) = (a xx b) xx c#

This is called the associative property of multiplication.

As a result of the associative property, we can write:

#a xx b xx c#

unambiguously without any parentheses.

Combining these two properties, we can multiply numbers in any order and always get the same result.

Advanced footnote

Note that above I said ordinary numbers. There are some strange kinds of numbers that do not conform to these rules:

  • Hamilton's quaternions drop the requirement that multiplication be commutative.

  • Octonions drop the requirement that multiplication be associative.

See https://socratic.org/questions/are-octonions-numbers for some more details.