a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
"Maths is essential for understanding the logic behind the quantity, shape, and arrangement in architectural design."
Clipping of mathematics.
"In British English, people often refer to their favourite subject as maths instead of mathematics."
Maths is simply a shortened form of the word mathematics that entered common usage to make it easier to say and write. It retains the original meaning but serves as an informal abbreviation for the study of numbers and quantities.