Notes Addition and Subtraction of Integers with counting chips

1
Notes Addition and Subtraction of Integers
(with counting chips)

• We are learning toadd and subtract positive and
  negative integers with counting chips.
• Monday, November 23, 2009

2
Counting Chips

• Take only the small red and blue Algebra Tiles
  out of the bag. Please put all other tiles back
  into the bag.
• Divide your tiles so that everyone in your group
  has an equal amount of tiles.

3
Rules for Counting Chips

• Today we will be modeling the addition and
  subtraction of integers with counting tile
  manipulatives.
• Rules
• When groups of different colored chips are put
  together a red and a blue chip cancel each other
  out.
• When groups of the same colored chips are put
  together nothing cancels out.

4
Practice

• DONT FORGET TO LABEL YOUR ANSWERS WITH THE
  CORRECT COLOR OF CHIPS
• 1. 3 reds 4 reds ________ 2. 5 blues 6
  blues ________
• 3. 2 blues 8 reds ________ 4. 8 reds 4
  reds ________
• 5. 9 blues 6 reds ________ 6. 7 blues 1
  blue ________

7 Reds
11 Blues
6 Reds
12 Reds
3 Blues
8 Blues
5
Fix the common mistake!

• Gordon was trying to add 13 blue chips to 15 red
  chips and he thinks that the solution is 28.
  Explain to Gordon what he did incorrectly. Help
  him fix his thinking so he wont answer future
  problems incorrectly.
• Explain in complete pictures and draw pictures to
  help Gordon!

6
Addition of Integers

• The Red Tiles representsone negative(-1).
• The Blue Tiles representsone positive (1).

7
More Practice

• DONT FORGET TO LABEL YOUR ANSWERS WITH THE
  CORRECT SIGN

-7
-14
-6
5
0
-3
Try the rest of the practice with your group!
8
Hints of adding integers

• If you are adding integers with the SAME
  signjust add like normal and keep the sign.
• If you are adding integers with DIFFERENT signs
  ask yourself 2 questions
• 1. Are there more positives or negatives? This
  will tell you the sign of your solution.
• 2. How many more do I have? This will tell you
  the value of your solution.

9
Subtraction of Integers

• Monday, November 23, 2009
• We are learning toadd and subtract positive and
  negative integers with counting chips.

10
Subtracting Integers with Counting Chips

• Subtraction means to take away, so to show this
  with chips we will have tostart with a certain
  amount of chips and then take away from that
  group.

-1
4
-5
-6
0
-7
Now try
PROBLEM ?
11
How can we take a negative away from a positive?

• Solution
• Add in Zero Pairs until you have enough
  negative (or positives) to take away!
• A Zero Pair is a positive and a negative chip.
• Since the two chips cancel each other, you are
  really adding in zero and not changing the
  problem.
• Remember

0

6
12
Subtraction of Integers Practice
9
-11
9
-14
3
-8
Now try a few assessment questions to test your
skills adding and subtraction integers!