* Some schools don't use A+ at all. Their highest grade is an A.
* Others might use A+ to denote a score slightly above 95% or 97%, while an A might be 90-94%. The exact cutoff is arbitrary and decided by the teacher.
* Some instructors might reserve A+ for exceptional work that goes beyond the requirements of the assignment. This might involve demonstrating exceptional critical thinking, creativity, or depth of understanding.
In short, you need to check your syllabus or ask your instructor to know their specific grading scale.