Hi, oh mighty ones!

I'm trying to enter this formula in Excel:

=IF(B2=a,10,"IF(B2=b,8,IF(B2=c,6)))")

According to the nested formulas rule, it's well-formatted (and I'm not even
using the seven-limit). This is to calculate how many points one gets
according to each school grade, A, B or C. HOWEVER...though it doesn't give
me an actual error message, the formula result cell tells me this:

#NAME?

Can someone tell me what I'm doing wrong? Thanks...