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To subtract positive integers: (+5) (+9)
We model the first number: +5
+5:
There are not enough tiles to take away +9. To take away +9, we need 4 more yellow tiles.
We add zero pairs without changing the value.
Add 4 yellow tiles and 4 red tiles. They represent 0.
By adding the zero pairs, the integer the tiles represent has not changed.
Now take away the 9 yellow tiles.
Since 4 red tiles remain, we write: (+5) (+9) = 4
Subtracting Integers with Tiles2.4
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Subtracting Integers with Tiles2.4
(6) (+2) =
1. Model the first number: 6
2. There are no yellow tiles to take away so we need 2 yellow tiles to be able to take away.
3. We add zero pairs. Add 2 yellow tiles and two red tiles.
4. Now take away 2 yellow tiles.
5. Since 8 red tiles remain, we write: (6) (+2) = 8
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(+2) (6) = 1. Model the first number: +2
2. There are no red tiles to take away so we need 6 red tiles to be able to take away.
3. We add zero pairs. Add 6 yellow tiles and 6 red tiles.
4. Now take away 6 red tiles.
5. Since 8 yellow tiles remain, we write: (+2) (6) = +8
Subtracting Integers with Tiles2.4
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Subtracting Integers with Tiles2.4
You try!
1. (2) (2) =
2. (6) (5) =
3. (9) (+7) =
4. (+5) (3) =
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Subtracting Integers with Tiles2.4
Notes for your journal:
Steps for Subtracting Integers with Tiles1. Model the first number in the equation with tiles.
2. If there are not enough tiles to take away, add zero pairs until you have enough to take away.
3. Cross off the tiles you are taking away.
4. Count up the left over tiles to find the answer.
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Subtracting Integers with Tiles2.4Assignment: p. 69: 1 (a,c,e), 2 (b,d,f), 3 (a,c,e), 4 (b,d,f), 5 (a,c,e), 7 IF YOU FINISH EARLY AND FEEL CONFIDENT IN YOUR ABILITY TO SUBTRACT INTEGERS USING TILES, PLEASE TRY QUESTION 12 AND 13.
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