To get the answer 9, it would need to be written (1+2)x3 or, technically, 3(1+2).
As others have said, multiplication takes precedence over addition so the sum should be read as 1+(2x3).
That's your maths lesson over with for today Dave - as it's the weekend we won't set you homework!
I am aware of BODMAS, but it worries me that some people doing important calculations are using basic calculators and others are using newer ones...
It reminds me of a rocket science problem which was attributed to a 'failed' probe deployment because one side (USA) were working in imperial and the other side (French, I think) were working in Metric - the net result was the probe was 'shot' from its position towards the planet rather than 'lightly floated'