I think the question might involve Lines 4 through 7 of the Form 8829:

4 Multiply days used for daycare during year by hours used per day 
5 If you started or stopped using your home for daycare during the year, see instructions; otherwise, enter 8,784

6 Divide line 4 by line 5. Enter the result as a decimal amount 
7 Business percentage. For daycare facilities not used exclusively for business, multiply line 6 by line 3 (enter the result as a percentage). All others, enter the amount from line 3 .