If Luke's scale for his drawing is 5m to 2cm, then it means that every 2cm on Luke's scale drawing represents 5m in real life. So since the width of the fountain is 2cm, the actual fountain width must be 5m. As established in the example, Isabella's scale factor from drawing to real life is 6/3=2, which means any measurement in cm on her drawing can simply be multiplied by 2 to obtain the real life measurement in m. So, to convert back the other way, from real-life to drawing, we just need to divide the value by 2 instead of multiply. So, if the real life value is 5m, then the width on her scale drawing should be 5/2 = 2.5cm.
