I'm guessing they did the 4 x 3, noticed they had to carry, accidentally wrote the carry in the wrong column, then immediately went and added that carry to their leftover 2, thus only counting 3 in total.
General rules:
Exceptions may be made at the discretion of the mods.
I'm guessing they did the 4 x 3, noticed they had to carry, accidentally wrote the carry in the wrong column, then immediately went and added that carry to their leftover 2, thus only counting 3 in total.