Question

which of the fractions are bigger 5/16 or 1/2 or 1/4 or 7/16

Answer 1

Change them all to equivalent fractions with the same denominator.

1/2 = 8/16
1/4 = 4/16

Now you can compare them:
5/16
8/16
4/16
7/16

Answer 2

1/4,5/16,7/16,1/2