Evaluate $6+5-4\times 3\div (2+1).$
I start with the parentheses and see that $2+1$ is $3$. Then I do the multiplication and division from left to right and see that $4\times 3$ is $12$ and $12\div 3$ is $4$. So I can rewrite the expression as $6+5-4$. Finally, I do the addition and subtraction from left to right and see that $6+5$ is $11$ and $11-4$ is $7$. 