How to Rearrange an Equation

Equations in algebra can be rearranged. Imagine we have an equation:

How to Add on a Number Line

Adding on a number line is easy.

Question

Use a number line to find 4 + 3.

Step-by-Step:

1

Find 4 on the number line.
4 + 3
number line add step 1

2

Move 3 to the right along the number line.
4 + 3
number line add step 2

3

Read off the number you have reached. number_line_add_step_3

Answer:

4 + 3 = 7

Lesson Slides

The slider below shows another real example of how to add on a number line.

Top Tip

To Add, Go Right

Adding means going right on a number line. adding_right

Note

The Order of Adding Doesn't Matter

In our example, we have found 4 + 3.

But the order in which we add the numbers doesn't matter... we can swap the numbers around:
4 + 3 = 3 + 4
This is the commutative property of addition: you can change the order of the numbers around the sign and still get the same answer.
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This page was written by Stephen Clarke.