User blog comment:AchieverBeaver88/Math probelms./@comment-3028286-20100921123839/@comment-1781822-20100924163227

Wow, you're still trying to work it out? Just use a calculator, but convert everything into centimeters first, like this:

19900 cm (length of what he wants his bedroom to be) - 12000 cm (length of bedroom) = 7900cm. Also, you asked how many centimeters, so if you think I lost my mind, take a closer look.