Worksheet for practicing addition of three integers with various combinations of positive and negative numbers.

Let's solve each of the problems step by step. We are adding three integers in each case, which includes positive and negative numbers.

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1) 7 + 18 + (-11)

First, add the first two numbers:
- $ 7 + 18 = 25 $

Then add the third number:
- $ 25 + (-11) = 25 - 11 = 14 $

✔ Answer: 14

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2) (-12) + (-4) + (-17)

Add all negative numbers:
- $ -12 - 4 = -16 $
- $ -16 - 17 = -33 $

✔ Answer: -33

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3) 21 + 2 + 12

All positive:
- $ 21 + 2 = 23 $
- $ 23 + 12 = 35 $

✔ Answer: 35

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4) 6 + (-15) + 1

First: $ 6 + (-15) = 6 - 15 = -9 $

Then: $ -9 + 1 = -8 $

✔ Answer: -8

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5) 8 + (-24) + (-14)

First: $ 8 + (-24) = 8 - 24 = -16 $

Then: $ -16 + (-14) = -16 - 14 = -30 $

✔ Answer: -30

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6) (-7) + 13 + (-2)

First: $ -7 + 13 = 6 $

Then: $ 6 + (-2) = 6 - 2 = 4 $

✔ Answer: 4

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7) 16 + (-1) + 11

First: $ 16 + (-1) = 16 - 1 = 15 $

Then: $ 15 + 11 = 26 $

✔ Answer: 26

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8) (-5) + (-16) + 3

First: $ -5 + (-16) = -21 $

Then: $ -21 + 3 = -18 $

✔ Answer: -18

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9) (-9) + 10 + 14

First: $ -9 + 10 = 1 $

Then: $ 1 + 14 = 15 $

✔ Answer: 15

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10) 20 + 17 + (-19)

First: $ 20 + 17 = 37 $

Then: $ 37 + (-19) = 37 - 19 = 18 $

✔ Answer: 18

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✔ Final Answers:

1) 14
2) -33
3) 35
4) -8
5) -30
6) 4
7) 26
8) -18
9) 15
10) 18

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Let me know if you'd like a visual explanation or want to practice more!