Define “math mechanics”. Rolling a die and adding a bonus is defined in this one sentence. Rolling with advantage or disadvantage doesn’t add much more. And that’s 99% of the math.

If you want an official publication, there’s the basic rules for 5e: https://www.dndbeyond.com/sources/dnd/basic-rules-2014

v5

• Addition
• Subtraction
• Multiplication
• Integer division (rounding down)
• Comparison with zero, set

https://orkerhulen.dk/Own made supplement/Easy combat reference chart.pdf

I keep one of these sheets around when running 3.5