CFAI Text - Book 5, reading 38 practice problem 2

In this questions, the answer key calculated the number of units using the rounded off number (1211) instead of 1212. (the calculated no, of units is actually 1211.11). However, in the text book page105 the similar example used the rounded up number. Why is there a discrepancy. Am I missing something? Thanks.

grade 3 rounding rules apply. if its < .5 round down. if its great than .5 round up. if its exactly .5 everyone writing the exam gets the question wrong. Its the CFAI way.

I started to feel like those who had to say" I am not smart than a 5th grader" on the show. In fact I am even worse…