To find the fraction of the whole pizza that each person will get when Joshua shares half of a pizza with three friends, you can express it mathematically. Joshua and his three friends make a total of 4 people sharing half a pizza.
The correct way to calculate this is to divide the half pizza by the number of people:
\[ \frac{1}{2} \div 4 \]
This means that you take half of a pizza and divide it among 4 people. Therefore, the correct expression from the options given is:
1/2 divide by 4.