1. same as counting numbers 2. first, second, third, ... 3. (... -4, -3, -2, -1, 0, 1, 2, 3, 4, ...) 4. (1, 2, 3, 4, ...) 5. a symbol consisting of three parts: a horizontal bar, a whole number above the bar, and a whole number other than zero below the bar 6. 10 in 104, it is the number to be used as a factor 7. 4 in 104, it is the number of times the base is to be used as a factor 8. number that divides evenly into another number 9. a factor that is also a prime number