EXPLANATION
Since we have 3 1/2 slices of cake, and we need to distribute a half of slice by each friend, we need to divide 3 1/2 by 2, as follows:
[tex]\frac{(3\frac{1}{2})}{2}=\frac{7}{4}=1\frac{3}{4}[/tex]
Therefore, since each friend gets a half slice of cake, we can affirm that each whole slice of cake can be divided into two halves.
Now, adding from half to half to obtain 3 1/2 slices of cake, give us:
1/2 + 1/2 + 1/2 + 1/2 + 1/2 + 1/2 + 1/2 = 7 slices
So, 3 1/2 slices of cake is a total of 7 halves.
Because each friend gets half of a slice of cake, we can affirm there are 7 friends.
