What is the natural language of computers mathematics or logic?
There is really no such thing as a natural language for computers. Natural language is a concept from linguistics, and pertains mostly to humans (and perhaps also to some animals).

The corresponding concept for computers is machine language or native code, which is what the computing core of the computer (the CPU) runs. Machine codes consists of various instructions, some of which perform arithmetic and logical operations. Others are in charge of control flow, of memory access, and so on.

Related to machine language is assembly code, which is a readable representation of machine code. While machine code consists of bytes, assembly code consists of textual symbols. (Assembly code also usually contains some features which make it a barebones programming language.)