Objective: Be able to add and subtract directed numbers.

First, you have to know the number line! 8 7 6 5 4 3 2 1 -1 -2 -3 -4 -5 -6 -7 -8 -9 If you remember what the number line looks like you will find this easy!

Let’s look at a question Work out +6 + -3 What does this mean? The first part tells you where to start on the number line. The last number tells you by how much. The symbols tell you what to do. If they are the same, you add. If they are different, you subtract

+6 + -3 Let’s do it So there’s your answer, 3 8 7 6 5 4 3 2 1 -1 -2 -3 -4 -5 -6 -7 -8 -9 One! Two! +6 + -3 Three! So there’s your answer, 3 They are different, so subtract… Start here … this much

+6 + -3 = 3

-4 - -9 Here’s another … They are the same, so we add… Start here 8 7 6 5 4 3 2 1 -1 -2 -3 -4 -5 -6 -7 -8 -9 -4 - -9 They are the same, so we add… Start here … this much So there’s your answer, 5