I don't have an idea about the 1st one but second one goes by subtracting 1/3 subtract 1/3 from 8 1/3 it's 8, subtract 1/4 from 8 it's 7 2/3. figuring out the patterns are simple most of the time bu you can get stuck sometimes, if you wanna get better, practice...
You can work out the pattern by subtracting the first number from the second. So for the first one, 7 1/2 (Which is equal to 7 2/4, because 1/2 = 2/4) - 7 1/4 = 1/4, so you add a quarter each time For the second one, 8 - 8 1/3 = -(1/3), so you subtract a third each time Hope that helps and isn't too confusing!
