What are the rules for working with negative numbers?

• When multiplying and dividing with negative numbers
  • Two numbers with the same sign makes a positive
    • e.g and 
  • Two numbers with different signs makes a negative
    • e.g.  and
  • For multiplication and division, it’s often easier to calculate ignoring any signs, then making a decision about whether the answer should be positive or negative
• When adding and subtracting with negative numbers
  • Subtracting a negative is the same as adding the positive number
    • e.g.
  • Adding a negative is the same as subtracting the positive number
    • e.g.