1. How many integers are there?
There are an INFINITE number of integers stretching back in the negative direction and forward in the positive direction, ←...-3, -2, -1, 0, 1, 2, 3...→
2. What is a negative integer?
A negative number is an integer that is less than zero. e.g. -3 is a negative number.
3. What sign does the answer have if I multiply a negative number by another negative number?
Strangely enough the answer is POSITIVE! e.g. -4 × -3 = +12
4. What is the difference between integers and natural numbers?
Natural numbers are the counting numbers N = {1, 2, 3, 4, ...}
Integers include 0 and all of the negative whole numbers {...-3, -2, -1, 0, 1, 2, 3...}
