It could be either 'sum' or 'add'.
Not having to spell the word "operation"!
Maths
maths
maths
Calculation means to do an operation such as add, subtract, multiply, divide, square or aquare root, etc. resulting in a numerical answer.
Maths (mathematics) is matamaitic.
maths/mathematics = mathématiques
It is usually a single character that is used to represent a mathematical object, operation, unit. Examples: P is a point. Square root is represented by "√" A degree is represented by "◦" But it could be multiple characters: ABC is a triangle.
Okaniwa and Operation Overlord
dandelion, diversion, operation
Usually another word for some frequently used mathematical formula.
seven (If numbers subject, corresponds to the subject dealing with the numbers, then it is Maths)