6/2(1+2)

Your calculator is correct; the expressions evaluates to 9.

 

Be careful with order of operations. Remember, there are strict rules when evaluating expressions. 
 

1. Evaluate Parentheses from left to right

2. Evaluate Exponents from left to right

3. Evaluate Multiplication or Division from left to right

4. Evaluate Addition or Subtraction from left to right

 

Okay, with these rules in place let's try to evaluate this expression

6/2(1+2)	This is the original expression. Do 1+2 first because it is in the parentheses.
6/2*3	Multiplication and division have the same priority. If there are multiple of these in an expression, evaluate them from left to right.
3*3	Evaluate 3*3
9	This is your final answer. And yes, your calculator is correct.

I think I know how you got your answer of 1:

 

6/2(1+2)	I think you evaluated this first just like above.
6/2*3	This is your mistake. You cannot do multiplication first as this it violates the order of operations.
6/6	At this point, you have calculated incorrectly, so your answer will be askew.
1

 

Just be vigilant on how you evaluate expressions because a mistake like the one I illustrated above can give you a wildly different answer.