In its simplest disguise, maths has to do with numbers. And numbers have to do with arithmetic operations.
The maths that economists use, is mainly statistics: the cumulation of numbers over the same kind of events or phenomena.
And since economists claim that money is a measure of wealth, 'financial maths' should have something to do with measuring.
Meter, kilogram, second have been defined as basic units for measuring space, matter and time. But so far,economists have avoided to define basic units for economic, monetary or financial measures. They have only come up with economic 'indicators' such as