Forum:Multiplication vs addition

Why it is accepted that "ab" means a multiplied by b, not just a with b (so, a added to b)? If we recall that a is apple, and b is banana, then why we have to multiply apple by banana when they're together? It's natural to let "ab = a+b", not "ab = a*b". Ikosarakt1 (talk ^ contribs) 09:17, June 21, 2014 (UTC)