Fractional part of a circle.
i posted a picture. would really appreciate it.

To find the remaining fraction and noting that the total is always 1 we can say:

r=1-1/2-3/8  to add subtract fractions you need a common denominator in this case 8 is the least common multiple so:

r=(8-4-3)/8

r=1/8

So 1/8 of the circle is shaded...