Party in Math-land
(an integer story)
Have you ever been to a party
like this?
Everyone is happy and having a
good time.
They are all Positive!
Suddenly, who should appear?
The Grouch! (one negative)
The grouch goes around
complaining to everyone about
the food, the music, the room
temperature, the other people…
What happens to the party?
Everyone feels less happy!
Everyone becomes negative!
My party
is ruined!
But wait! Another guest is
arriving…
The new guest is another grouch.
The two negative people get
together…
They start complaining to each other
about how miserable they are…
And look! They are starting to
smile and have a good time…
Pairs of negatives become
positive!
The
party is
saved!
Now that the two grouches are
together the rest of the people
(who were really positive all
along) become happy once again.
The moral of the story…
When multiplying and
dividing integers, one
negative make all positives
negative, but two negatives
become positive!
Therefore, the following rules apply:
+·+=+
+·-=-
-·+=-·-=+
Now, let’s practice!