Deductions & credits

You don't understand! Ok, we're talking square footage rather than rooms, but my point remains the same. On the screen entitled "How Big is This Home Office?" TT only allows me to enter the number of square feet I use exclusively for my business. But, I'm not using any square feet exclusively. If I enter all the square feet as exclusive use, my business use % is 100%, but that's wrong. How can I enter regular use square footage? I previous years TT asked questions about how much time I was using my home for business, but I don't see that anywhere. Daycare has special rules about calculating the business use of home, but TT doesn't seem to recognize this, as it did in previous years. Did I miss this somewhere?