represent and compare numbers
less than 0 by extending the number line.
What are
integers?
It's a cold winter morning. You
turn on the television and the weather man says that the temperature
outside is "minus 10 degrees". The number minus ten
is actually the number -10, or negative ten, an integer. The term
integer is meant to describe the signed numbers.
A formal definition would be integers
are all of the whole numbers and their opposites. Remember,
whole numbers are the numbers 0, 1, 2, 3, 4, 5,...and so on. These
numbers are positive numbers because they are
to the right of 0 on the number line. Up until now you have always
written these without a sign, but now you will probably be putting
the + in front of them. So the number 5 is can be written +5.
Every positive number has an opposite
on the other side of the number line. These are the negative
numbers. They are the numbers to the left of zero. Every
negative number has the - sign. So negative five is written -5.
0 is neither positive nor negative.
Below you see three integers marked
on the number line. Find the opposite of each integer and then
click the buttons to see if you were correct.
Every integer stands
for a number in the real world. Negative integers are used to
represent situations when something has been lost (as in money)
or dips below zero (like the temperature example above). Positive
integers represent situations when something has been added (such
as yardage in a football game) oris above zero (like sea level).
