Variation on mental maths

[BradKML]

Here are some proposals:

1. totaling X amount of Y numbers (e.g. arithmetic on 8d6 on RPGs)
   • amount quantity minimum and maximum (possible default: 2 to 20)
   • number range minimum and maximum (possible default: 2 to 12)
2. mixing multiplication with addition/subtraction (e.g. Multiple Items, Taxes or Service Charge, with tips)