 Number line with integers

Lesson

Number lines go on forever and include both positive and negative numbers. As we move to the right along the number line, the numbers get bigger.

As we move to the left, the numbers get smaller.

In other words, the further a number is to the right on a number line, the larger it is, and the further it is to the left, the smaller it is.

When a number is plotted on the number line, we can tell what the number is by looking at the number labels and the spacings and counting up or down.

Examples

question 1

What number is represented by the point on the number line? Think: The marks on the number line are increasing $1$1 at a time.

The point is $1$1 space to the right of the number $5$5, so we need to count up $1$1 number from $5$5.

Do: $5+1=6$5+1=6, so the number represented by the point is $6$6.

Question 2

Here's an example with a negative number.

What number is represented by the point on the number line?

Moving along the number line

Once we can locate a number on a number line, we can use it as a starting point to move up and down the number line to find other directed numbers.

Examples

question 3

What number is $3$3 spaces to the left of the point marked on the number line below? Think:  We are starting at $8$8 and need to move $3$3 spaces to the left, so we can use the number line to count back $3$3 spaces.

Do: $8-3=5$83=5

So the number $3$3 spaces to the left is $5$5.

question 4

Let's look at an example with negative numbers:

What number is $6$6 units to the left of the marked point?

question 5

What number is $8$8 units to the right of the point marked on the number line?

Question 6

Which of the following numbers lies furthest to the left on the number line?

1. $4$4

A

$-8$8

B

$-4$4

C

$4$4

A

$-8$8

B

$-4$4

C