I am by no means a math wizard nor am I familiar with that particular pattern but here goes. If I take 100 inches wide and divide by 4.5 inches (finished size of your block) I get 22.22222 so I would do 23 blocks wide if you plan to have no borders. Or go down to 22 blocks if that works out better to get to the length you need and then do a border or 3 to get to the actual finished size you need.
I'm sure others more familiar with the pattern and better at math will be along shortly.
Good luck.