My most commonly used math functions are (in no particular order):
- Average
- Medium
- Max / Min
- Length/Count
- Add / Increment
- Subtract / Decrement
- Average
- Medium
- Max / Min
- Length/Count
- Add / Increment
- Subtract / Decrement
1. Weighted average 2. Percentage calculations 3. Absolute number
Thats it I can think of for doing financial software development for the past 10+ years.