Mathematics

INTEGER RULES

Here's How:

1. Adding Rules:

   Positive + Positive = Positive: 5 + 4 = 9
   Negative + Negative = Negative: (- 7) + (- 2) = - 9

   Sum of a negative and a positive number: Use the sign of the larger number and subtract

   (- 7) + 4 = -3
   6 + (-9) = - 3
   (- 3) + 7 = 4
   5 + ( -3) = 2

2. Subtracting Rules:

   Negative - Positive = Negative: (- 5) - 3 = -5 + (-3) = -8
   Positive - Negative = Positive + Positive = Positive: 5 - (-3) = 5 + 3 = 8
   Negative - Negative = Negative + Positive = Use the sign of the larger number and subtract(Change double negatives to a positive)
   (-5) - (-3) = ( -5) + 3 = -2
   (-3) - ( -5) = (-3) + 5 = 2

3. Multiplying Rules:

   Positive x Positive = Positive: 3 x 2 = 6
   Negative x Negative = Positive: (-2) x (-8) = 16
   Negative x Positive = Negative: (-3) x 4 = -12
   Positive x Negative = Negative: 3 x (-4) = -12

4. Dividing Rules:

   Positive ÷ Positive = Positive: 12 ÷ 3 = 4
   Negative ÷ Negative = Positive: (-12) ÷ (-3) = 4
   Negative ÷ Positive = Negative: (-12) ÷ 3 = -4
   Positive ÷ Negative = Negative: 12 ÷ (-3) = -4

Tips:

1. When working with rules for positive and negative numbers, try and think of weight loss or poker games to help solidify 'what this works'.
2. Using a number line showing both sides of 0 is very helpful to help develop the understanding of working with positive and negative numbers/integers.

http://math.about.com/od/prealgebra/ht/PostiveNeg.htm