Bones and other artifacts have been discovered with marks cut into them that many believe are tally marks. These tally marks … See more

Numbers can be classified into sets, called number sets or number systems, such as the natural numbers and the real numbers. The main number systems are as follows:
Each of these number systems is a subset of the next on… See more

An even number is an integer that is "evenly divisible" by two, that is divisible by two without remainder; an odd number is an integer that is not even. (The old-fashioned term "evenly divisible" is now almost alw… See more

Algebraic numbers are those that are a solution to a polynomial equation with integer coefficients. Real numbers that are not rational numbers are called irrational numbers. Complex numbers which are not algebraic a… See more

The p-adic numbers may have infinitely long expansions to the left of the decimal point, in the same way that real numbers may have infinitely long expansions to the right. The number system that results depends o… See more

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• Concrete number
• List of numbers
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• Mathematical constant – Fixed number that has received a name… See more