Page 23 - Math Course 1 (Book 1)

Adding Integers

MO. 1 - L3b
Add Integers with Different
Adding two integers with Signs

Different Signs
Examples

Let’s Begin Find –9 + 10.

–9 + 10 = 1 To f nd –9 + 10, subtract |9|
from |10|. The sum is positive
because |10| > |9|.
Add Integers on a Number Line
Answer 1
Examples

Find 7 + (–11). Find 8 + (–15)

-11 8 + (–15) = –7 To f nd 8 + (–15), subtract |8|
from |–15|. The sum is
7 negative because
|–15| > |8|.

Answer -7
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Start at zero.

Move 7 units to the right.
Your Turn!
From there, move 11 units to the left.

7 + ( -11 ) = -4 Add Integers with Different
Answer
Signs

Find –2 + 9 Find –6 + 11
9 Answer
A. 5
-2 B. -5
C. 17
D. -17

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Start at zero.
Find 4 + (–7).
Move 2 units to the left. Answer
A. 11
From there, move 9 units to the right. B. -11
C. 3
–2 + 9 = 7 D. -3
Answer

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