Number Line

Writing numbers down on a Number Line makes it easy to tell
which numbers are greater or lesser

greater less
number line -10 to +10
Negative Numbers (−) Positive Numbers (+)
(The line continues left and right forever.)

 

A number on the left is less than a number on the right.

Examples:

A number on the right is greater than a number on the left.

Examples:

Try this interactive number line (click to mark):

You can also try the zoomable number line.

lunch

Example: Lunch

Place these people on the number line to find who is poorest and who is richest.

Owing money is negative
Having money is positive

So John has "3", Virginia has "5" and Alex has "+3"

greater less
number line: -5,-3,3

Now it is easy to see that:

Virginia is poorer than John (−5 is less than −3)
and John is poorer than Alex (−3 is less than 3)
and Alex is, of course, the richest!

Using The Number Line

We can use the number line to help us add. We always move to the right to add.

We can use the number line to help us subtract. We always move to the left to subtract.

Read How to Use the Number Line to Add and Subtract.

 

Footnote: Absolute Value

Absolute Value means to think only about how far a number is from zero.

absolute value -6 is 6, 6 is 6

For example "6" is 6 away from zero, but "−6" is also 6 away from zero.

So the absolute value of 6 is 6, and the absolute value of −6 is also 6