I disagree qatarisun. Having studied maths throughout my education (GCSE, A-Level, Masters degree) I have had it drilled into me that you should always include brackets in order to clarify whether multiplication/division or addition/subtraction comes first. If I wrote that equation in an exam paper I would expect to be marked down.

Surely the fact that different calculators work it out differently shows that the standard of multiplication first is not universally followed!

There are two ways to write the equation - with and without brackets. Writing it without them has caused confusion and resulted in the incorrect answer. Hence the equation was written poorly, as it would have taken very little to include the brackets.

I do agree with you about a lot of people having no knowledge of basic maths though!