Adding & Subtracting –ve no.s 3 + 4 -6 + 3 -7 - 3 = 7 = -3 = -10 + + − Here explain how to use it, the first number in an addition/sub sum is the starting number, point your finger on the starting number, the sign of the second number tells you in which direction you are going to go ! - + -1 + 6 = ? -7 + 4 = ? -2 + 2 = ?

Summary −3 – 4 = − 7 +3+4 = +7 −3+4 = +1 3−4 = −1 (keep walking in the negative direction) +3+4 = +7 (keep walking in the positive direction) −3+4 = +1 (If the bigger number has a positive sign, just minus the numbers, the answer is positive) 3−4 = −1 (if the bigger number has a negative sign, minus the numbers number, the answer is negative)

I will still have €3 debt ! (-3) Reason it out.. 𝒂.) 𝟖 – 𝟏𝟏 = −𝟑 A.) Using the Number Line B.) Using Money I have €8 in my pocket (+8) I have €11 debt (-11) (money to give : dejn!) I can give the €8 I have in my pocket BUT I will still have €3 debt ! (-3)

Reason it out.. 𝒃.)−𝟑 + 𝟓=𝟐 A.) Using the Number Line B.) Using Money I have €3 debt (-3) (money to give : dejn!) I have €5 in my pocket (+5) I can give the €3 from my pocket AND I will still have €2 left in my pocket! (2)

Reason it out.. 𝒄.) −𝟓−𝟐+𝟑+𝟏=−𝟑 A.) Using the Number Line B.) Using Money I have €𝟓 𝐝𝐞𝐛𝐭 I have €𝟐 𝒅𝒆𝒃𝒕 In all I have €7 debt I have €𝟑 𝐢𝐧 𝐦𝐲 𝐩𝐨𝐜𝐤𝐞𝐭 I have €𝟏 𝒊𝒏 𝒎𝒚 𝒑𝒐𝒄𝒌𝒆𝒕 In all I have €𝟒 I can pay €4 BUT will still need to pay €3 (-3)

What about when the signs are together? Two positives? 9 + + 1 Two negatives? 4 - - 3 Neg & pos? 4 - + 3 Pos & Neg? 4 + - 4

I do not (-) not (-) want a chocolate I WANT (+ve) a chocolate !!!! Two negatives? I do not (-) not (-) want a chocolate means I WANT (+ve) a chocolate !!!!

Friend or Enemy?

+ 8 - - 6 = 14 Look at the signs in the middle, if they are the same, then replace them with +

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

-6 + -2 = -6 - -8 = -8 2 But what about this one? - + -6 - -8 = -8 2 + Remember: This is your start number and the new sign in the middle is the direction

Summary – When signs are together They become ONE SIGN SAME SIGNS  BECOME A PLUS DIFFERENT SIGNS  BECOME A MINUS

MINI-PLENARY (SIMPSONS) Work out: -5 – 9 a) 14 b) 45 c) -45 d) -14

MINI-PLENARY (SIMPSONS) Work out: 8 - - 9 a) 17 b) -1 d) 1 c) -17

Multiplication is repeated addition What is 2 x 4? Read this question using normal words: “2 for 4 times” 2 + 2 + 2 + 2 = 8 Multiplication is repeated addition

What is -2 x 4? Read this question using normal words: “ minus 2 for 4 times ” -2 -2 -2 -2 = -8

Multiplying and Dividing SAME SIGNS DIFFERENT SIGNS POSITIVE ANSWER 8 x 2 = 16 (+ × + = +) -8 x -2 = 16 − × − = + 24 ÷ 6 = 4 + ÷ + = + -24 ÷ -6 = 4 (− ÷ − = +) NEGATIVE ANSWER -8 x 2 = -16 − × + = − 2 x -8 = -16 ( + × − = −) -24 ÷ 6 = - 4 (− ÷ + = −) 24 ÷ -6 = - 4 ( + ÷ − = −)