Appendix+Appendix = sum (the sum of the positions of the exchange addend remains unchanged). Minus-Minus = difference. Sum = tooth tip+tooth tip difference = minus-minus. Sum-addend = another addend is minuend-difference = minuend. Another addend = sum-complement minus = minus-difference. Difference+subtraction = subtraction. Subtraction = difference+subtraction.
Find how much a large number is more than a decimal, and work it out by subtraction (-). Find how much the decimal is less than the large number, and work it out by subtraction (-). Large number = decimal number+superfluous number decimal number = large number-superfluous number = large number-decimal number.
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Mathematics is a universal means for human beings to strictly describe and deduce the abstract structure and mode of things, and can be applied to any problem in the real world. All mathematical objects are artificially defined in essence.
In this sense, mathematics belongs to formal science, not natural science. Different mathematicians and philosophers have a series of views on the exact scope and definition of mathematics.
Mathematics is a universal means for human beings to strictly describe the abstract structure and mode of things, and can be applied to any problem in the real world. In this sense, mathematics belongs to formal science, not natural science. All mathematical objects are artificially defined in essence. They do not exist in nature, but only in human thinking and ideas.