See also the Dr. Math FAQ: 3D and higher Browse Middle School
Number Sense/About Numbers Stars indicate particularly
interesting answers or good places to begin browsing. Selected
answers to common questions: Multiplying by zero. Casting out
nines. Number facts from the Web. - Inequalities on a Number
Line [05/07/2003] How do you graph inequalities on a number
line? - Infinite Number of Primes [04/14/1998] Prove there are
an infinite number of primes. What is the largest prime -
Infinity [5/24/1996] Is infinity positive or negative? -
Infinity and Inequalities [06/05/2002] I'm supposed to use
positive and negative infinity to solve problems like 2x - 3 <
7. - Infinity minus Infinity [10/26/1995] Infinity - Infinity =
? - Infinity Plus One [12/26/1995] What is infinity plus one? -
Infinity times Infinity [10/15/1998] What is infinity multiplied
by infinity? - Integers and Rational Numbers [5/25/1995] Can you
explain the difference between SET Q (rational numbers) and SET
Z - Integers in Everyday Life [01/16/20