Grade 9 Math (MTH1W) – Cycle 1 – Ms. Strome – Complete Notes and Answer Key for Lessons 1.2–1.13

MTH1W - Grade 9 Math
Ms. Strome




CYCLE 1 - NOTES



Name : ____________________

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, 1.2 & 1.3 Adding, Subtracting, Multiplying and Dividing Integers

A.​ Integers

An integer is a _____________ or _____________ whole number (ex: )
​
B.​ ADDING and SUBTRACTING Integers

When adding AND subtracting integers, check to make sure there are no “double signs”, always fix
these first! (**double signs can have a bracket in between but NOT a number!)

Double Sign Rules
Same Signs ​ ​ ​ ​ ​ ​ Different signs
+ (+) = ​ or ​ − (−) = ​ ​ ​ − (+) = ​ ​ or ​ + (−) =

Example 1 -Number Line


a)​ ​ ​ ​ ​ b)




c)​ ​ ​ ​ ​ d)




Example 2 –More negatives or positives? Hint: Fix double signs 1st!


a) ​ ​ ​ ​ ​ b) ​
​ ​ ​ ​

c) ​ ​ ​ ​ ​ d)



e) ​​ f) ​
​
C.​ MULTIPLYING and DIVIDING Integers
When multiplying AND dividing integers, use the rules for double positives and negatives:
++​ POSITIVE​ + -​ NEGATIVE​ --​ POSITIVE​ ​ - +​ NEGATIVE
a) ​ ​ ​ ​ ​ b) ​

, 1.2 & 1.3 Adding, Subtracting, Multiplying and Dividing Integers


CHECK YOUR UNDERSTANDING:




1.​ Use the number line above to help you evaluate each sum. Remember to eliminate any
double signs first!

a)​ 8 + 5 =​ ​ ​ b) − 2 + 5 =​ ​ ​ c) − 7 + 3 =

d) 3 + (− 5) =​​ ​ e) 5 + (− 2) =​ ​ ​ f) − 4 + (− 6) =

g) − 11 + 4 + 5 =​ ​ h) − 2 + 2 + 5 =​​ i)− 5 + (− 3) + 3 =


2.​ Evaluate the following:

a) 7 + 9 =​ ​ ​ ​ b) − 9 − 6 =​ ​ ​ c) − 12 + 4 =​

d) − 4 + 7 =​ ​ ​ e) 3 – (− 9) =​ ​ f) 1 + 3 + (− 6) =

g) − 2–6 + 4 =​ ​ ​ h) − 1–2–4 =​ ​ ​ i) 17–(− 5) =​

j) − 3 + 5–9 =​ ​ ​ k) 14 + (− 3)–(− 5) =​ ​ l) 7–(− 3) + 3 =

m) − 2–(− 8) =​ ​ ​ n) 7 – 9 =​ ​ ​ ​ o) − 3–5 =​ ​


3. Find each product.

a) 4×6 =​ ​ ​ ​ b) 2×(− 9) =​ ​ c) (− 5) × (− 7) =

d) (− 4)(− 6) =​ ​ ​ e) 7(− 3) =​ ​ ​ ​ f) − 3(− 4) =


4. Find each quotient.

a) 20÷5 =​ ​ ​ ​ b) (− 12)÷4 = ​ ​ ​ c)− 35÷(− 7) =

−24 −20
d)− 9÷9 =​ ​ ​ ​ e) 8
=​ ​ ​ ​ f) −5
=




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