[meyer]

I think part of the problem is using "keyboard" notation instead of hand-written math. I think it throws people off as to positioning and grouping and such. It's just a little caddywhompus!

Using x for the value 48 would give x/2(9+3) as the equation.

Perhaps because I have been jaded by my computer science background, I read that as x/2 times the parenthetical sum.

Whereas I can see x/24 as a possible answer.

[SoothingDave]

I think the major disconnect here is between those who see a “/” sign and just assume that everything after it is in the denominator of the division expression.

And those who see “/” as a mathematical operation between expressions on either side of it.

The former force implied parentheses into their evaluation.

The latter do not.

[MortMan]

I agree that handwritten notation is cleaner, but I would note that precedence rules says that the horizontal line is a form of parenthetical - it specifies precedence.