The confusion is caused by order of operations, in this case, whether division or multiplication should be done first. The question, in fact, is:
6 / 2 * 3 as brackets always go first.
Instead of determining the order of operations, let's change the division into mutiplication:
6 * 1/2 * 3
Now, we only have multiplication, but let's make it even easier than that. Let's change all numbers into fractions:
6/1 * 1/2 * 3/1
We multiply fractions by multiplying the numerators:
6 * 1 * 3 = 18
and by multiplying denominators:
1 * 2 * 1 = 2
As a result, we have a fraction:
18 / 2
and the answer is 9.