1. Objectives By the end of the lesson students will:
Understand requirements and structure of GCSE Maths course.
Know what is available on Boodle and how to access it.
Be able to perform calculations with negative numbers, e.g. −3−6
7−−2
9×−5

2. Negative and Positive Numbers

3. Adding and Subtracting Numbers

4. Adding and Subtracting Numbers
= 1
= - 7
This is our start number
This is the number of places we need to move
This is the direction of move - +

5. Add Same Signs + = 14
Look at the signs in the middle, if they are the same, then replace them with +

6. - 8 + - 6 = 2 Subtract If Different
Look at the signs in the middle, if they are different, then replace them with -

7. -6 + -2 = -6 - -8 = -8 2 What about this one? - +
Can you use all your knowledge of
negative numbers so far to find the
answer to these calculations? - = = -8 2 +
Remember: This is your start number and the new sign in the middle is the direction

8. Adding and Subtracting Numbers
Add positive number 
 Subtract positive number
 Add negative number
Subtract negative number 
8 – -5 is the same as 8 + 5
is the same as -7 – 2
-10 – -12 is the same as
is the same as 13 – 4

9. Multiplying Numbers…
Positive x Positive = Positive 6 x 7 = 42 Negative x Negative = Positive -6 x -7 = 42 Negative x Positive = Negative -6 x 7 = -42 Positive x Negative = Negative 6 x -7 = -42

10. Dividing Numbers…
Positive ÷ Positive = Positive 42 ÷ 7 = 6 Negative ÷ Negative = Positive -42 ÷ -7 = 6 Negative ÷ Positive = Negative -42 ÷ 7 = -6 Positive ÷ Negative = Negative 42 ÷ -7 = -6