To figure out the number we need to set up our equation to make more sense.
3/5 = 30/x (x is our missing number)
We know that what ever you do to the top of the fraction you can do to the bottom.
So if we multiply 3 x 10 we get 30.
Therefore to get the number we must multiply 5 by 10
5 x 10 = 50
So our answer and missing number is 50
