This document provides a review of key concepts in grade 9 math including: 1) Rules for adding and subtracting integers such as same sign equals add, different signs equals subtract the numbers and use the sign of the higher number. 2) Methods for multiplying and dividing integers including even numbers of negatives equals a positive and odd numbers of negatives equals a negative. 3) Procedures for adding, subtracting, multiplying and dividing fractions including using a common denominator. 4) The order of operations for BEDMAS including performing operations inside brackets first then exponents, division and multiplication, addition and subtraction.

1. Review unit grade 9

2. Integers +5 -9Add ……Same signadd the numbers, use the sign-3 + -7 = -10Different signssubtract the numbers, use the sign of the higher number3 + -7 = -4

3. Integers +5 -9Subtract……Change to add-3 - -7 = -3 + 7 = 4

4. Integers -5 +9Multiply or divide…….2 numbers + - = -- = ++ + = +More than 2 numbersEven number of - = +Odd number of - = -

5. FractionsAdd or subtract…Common denominator+  =  +  = Multiply….Multiply across• = DivideInvert and multiply÷ = • = 

6. BedmasPay close attention to order of operationsbrackets, exponents ,div and mult, add and subtract { 3 – 5 }2 ÷ 2 – 7 • 2 {-2}2÷ 2 – 7 • 2 4 ÷ 2 – 7 • 2 2 - 14 -12

7. Square Roots √52 of the same number multiplied to get what’s under the square root sign√ 144 = 12Because 12 • 12 = 144

8. GeometryFinding angle measuresAngle measure of a straight line = 180°Opposite angles are =1483232