Integers

Integers

1. are composed of

   • opposite of positive numbers
     • Eg. -1 , -2 , -3 , -4 , ...
     • value less than 0
   • zero
     • neither negative nor positive
     • considered neutral
   • counting numbers
     • any regular number
     • Eg. +1 , +2 , +3 , +4 , ...
     • value greater than 0

2. can be represented using a number line

3. Adding integers

   • Same signs
     • Add the numbers and keep the sign
       • (+) + (+) = (+)
         • Example : 5 + 3 = 8
       • (-) + (-) = (-)
         • Example : (-5) + (-3) = (-8)
   • Different signs
     • Subtract the two numbers and keep the sign of the bigger number
       • Example : (-8) + 2 = -6
       • Example : 8 + (-2) = 6

4. Subtracting integers

   • To subtract integers, LCO the problem
     • Leave the first number
     • Change the last number to its Opposite
     • Change the sign
     • Use the addition rules to solve
     • (-7) - (-4)
       • L C O
         • (-7) + (+4)
           • = -3
     • 7 - (+4)
       • L C O
         • 7 + (-4)
           • = 3

5. Multiplying Integers

   • If the signs are the same, you multiply and the product is positive
     • (+) x (+) = (+)
     • ( - ) x ( - ) = ( + )
     • Example : ( -4 ) x ( -2 ) = +8
   • If the signs are different, multiply and the product is negative
     • ( + ) x ( - ) = ( - )
     • ( - ) x ( + ) = ( - )
     • Example : ( - 4 ) x ( 2 ) = ( - 8 )

6. Dividing Integers

   • If the signs are the same, you divide and the quotient is positive
     • ( + ) / ( + ) = ( + )
     • ( - ) / ( - ) = ( + )
     • Example : ( - 8) / ( - 2 ) = ( + 4 )
   • If the signs are different, you divide and the quotient is negative
     • ( + ) / ( - ) = ( - )
     • ( - ) / ( + ) = ( - )
     • Example : ( - 8 ) / ( + 2 ) = ( - 4 )