$200$ times what is $100$? This number will be the denominator, or the bottom of the fraction, in your Giant One.
Remember, in a Giant One the numerator, or the number on top, and the denominator will be the same so that the fraction is equal to one.

$\text{Here your Giant One should be: } \frac{0.5}{0.5}.\$

$\text{Can you multiply}\\ \frac{85}{200}\ \text{and}\ \frac{0.5}{0.5} \text{to get a }$

$\text{new fraction with a denominator of } 100?$

$\frac{85}{200}=\frac{42.5}{100}$

Were you able to find the percent equivalent?

$\frac { 4 } { 5 } = \frac { x y } { 100 } = 80 \%$

$15$ times what will be equal to $100$?
Try using division to find your Giant One's denominator and numerator.

The fraction will be equivalent to $\frac{113.\overline{3}}{100}$.

What would this be as a percent?