8087 was the first math coprocessor for 16-bit processors designed by Intel.
It was built to pair with 8086 and 8088. The purpose of 8087 was to speed up the computations involving floating point calculations. Addition, subtraction, multiplication and division of simple numbers is not the coprocessor’s job. It does all the calculations involving floating point numbers like scientific calculations and algebraic functions.
Reference : http://www.eazynotes.com/notes/microprocessor/Slides/math-co-processor-8087-handouts.pdf