calculator error?

why does 6/2(1+2)=1 when your calculator says 9

Because calculators have built into them DIFFERENT order of Math operations. And it's different from country to country.In some countries they take multiplication first & followed by division. Other countries use exactly the opposite, that's division first and then followed by multiplication. Follow the convention used in your country. So, your calculator is taking the brackets first, which is 3. Then it's doing the division next(6/2)=3 and then multiplying them together next to get 3 X 3=9.

9 is correct

6/2 (1 + 2)  =

3 (3)  = 9

For 1 to be correct we must have

6/ [2(1 +2)] =

6/ [2(3)]=

6/[6] = 1

This shows that the placement of parentheses and/or brackets IS important   !!!