# 11-3: Subtracting Integers

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11-3: Subtracting Integers
The University of Texas at Dallas

1. Use Color Counters 2. Mentally

SUBTRACTING INTEGERS (using color counters)
We often think of subtraction as a “take away” operation. Which diagram could be used to compute = ? +3 +3 The University of Texas at Dallas

SUBTRACTING INTEGERS (using color counters)
This diagram shows adding 2 zero pairs. Now we can take 5 yellow tiles away, we have 2 red tiles left. We can’t take away 5 yellow tiles from this diagram. There is not enough tiles to take away!! The University of Texas at Dallas

SUBTRACTING INTEGERS (using color counters)
Use your red and yellow tiles to model each subtraction problem. = ? ANSWER The University of Texas at Dallas

-2 - -4 = +2 SUBTRACTING INTEGERS Now you can take away 4 red tiles.
2 yellow tiles are left, so the answer is… This representation of -2 doesn’t have enough tiles to take away -4. If you add 2 zero pairs(adding zero) you would have a total of 4 red tiles and the tiles still represent -2. = +2 The University of Texas at Dallas

SUBTRACTING INTEGERS (using color counters)
Work this problem. = ? ANSWER The University of Texas at Dallas

+3 - -5 = +8 SUBTRACTING INTEGERS
Add enough zero pairs so you can take away 5 red tiles. Take away 5 red tiles, you have 8 yellow tiles left. = +8 The University of Texas at Dallas

SUBTRACTING INTEGERS (using color counters)
Work this problem. = ? ANSWER The University of Texas at Dallas

-3 - +2 = -5 SUBTRACTING INTEGERS
Add two zero pairs so you can take away 2 yellow tiles. Take away 2 yellow tiles, you have 5 red tiles left. = -5 The University of Texas at Dallas

Subtracting Integers Mentally, then check using color counters.
When you subtract integers you…….. ADD the OPPOSITE !!!! 9 – (-2) +3 – (-1) -5 – (-8) -7 - 6

Practice Time  P 585 # 1-7