Operations with Negatives and Decimals

1.)  7+(-4)=?

• • (+)(+)(+)(+)(+)(+)(+)  (-)(-)(-)(-)  <- Represent as 7 + objects and 4 – objects
  • (+)(+)(+)  <- Remove 4 + objects because the 4 – objects cancel the + objects
  • 3 count the objects left

2.)  -8-5=-13

• • (-)(-)(-)(-)(-)(-)         (-)(-)(-)(-)(-) <- Represent -8 as – objects and -5 as -5 objects
  • (-)(-)(-)(-)(-)(-)(-)(-)(-)(-)(-) <- Combine the 2
  • 11 <- Count the objects

3.)  -2 x 3 = -6

4.) -2 x (-3) =6

• For multiplication and division, 2 negative signs give a positive value

• Move decimal so divisor is a whole #
• move dividend decimal the same amount
• divide
• Then, replace the decimal

3.265 -> decimal is 3 places over

0.96 -> decimal is 2 places over

3+2=5 <- The decimal is 5 places over

3.1344