Rules

Rules for adding, subtracting,

 

multiplying and dividing

 

rational numbers

 

Addition Rules

1st Rule  --  If the signs are the same add and keep the same sign.

                                                           Ex: (-5 + (-5)= -10)

2nd Rule  --  If the sign are different subtract and keep the sign of the larger number.

  Ex: (5 + (-7)= -2)

 

Subtraction Rule

Change sutraction to addition and change the next number to its opposite then look back at the addition rules to finish the problem.

Ex: (-5 - 5=? change to -5 +(-5) = ? the 2nd rule of addition applies to find the answer (Same signs add = -10).

 

Multiplication and Division Rules (these rules are the same)

1st rule -- same signs positive answer Ex: -25 x (-5) = positive 125   

                                                             Ex: -25    (-5) = positive 5

 2nd rule  --  different signs negetive answer Ex: 25 x (-5) = negative -125

                                                                       Ex: -25 ÷ 5 = negative -5

 

Videos to help with rules

 

 

 

 

 

 

 

Rules must exist

 

Without rules this would be a world you would not what to live in. Well math is the same. Without rules, math would not exist. Every part of math stands on rules which if you learn them  math is easy.