You can make 4 wholes from 8 halves.
There are 16 halves in eight wholes.
There are only 2 halves to any number. If you mean how many halves are in 4 wholes: Since there are 2 halves to a whole, you multiply 2 x 4, which gives you a total of 8 halves in 4 wholes.
10 halves in 5 wholes.
You can make 3 wholes
20
5 wholes = ten halves plus one half = 11 halves
12
1
8
8 wholes with one half left over
3 x 2 = 6 halves