Remember, 7 can be written as 7/1, so now we have:
$$\frac{7}{2} \div \frac{7}{1}$$
Now remember, when dividing two fractions, we can SKIP, CHANGE, FLIP. We SKIP the frist fraction, CHANGE the division sign to a multiplication sign, and FLIP the second fraction. So now we get:
$$\frac{7}{2} \times \frac{1}{7}$$
Multiply the tops together, and the bottoms together.
$$\frac {7\times1}{2\times7}$$
$$\frac{7}{14}$$
We can reduce this by dividing the top and bottom by 7, and then we get:
$$\frac{1}{2}$$
And that's our final answer.
