How do you know 1 and 2/3 divided by 3 and 1/2 has to be less than 1/2, without calculating the quotient?

Please explain :)

because 1 2/3 * 2 = 3 1/3, which is less than 3 1/2

or, 1 2/3 = 5/3 = 10/6
3 1/2 = 3 3/6 = 21/6
and 10 is less than half of 21