You see, Tobias WOULD have tried doing the additions but he was in a bit of a pickle for a few reasons.

1. He hadn't been writing the numbers down and had forgotten basically all of them
2. His maths skills were shocking and somehow he always managed to screw up even the simplest of sums
3. Someone had DEFINITELY called out the number 'R2D2' and Tobias hated algebra

Still, he bent over his parchment anyway and made a few notes. Namely what they'd done so far, calling out random numbers and having to add them. Just in case it was important. Maybe. Somehow.

Someone else could do the difficult part; there were a ton of Ravenclaws AND West Odessa in here.