Lesson How to Add and Subtract Negative Numbers

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This Lesson (How to Add and Subtract Negative Numbers) was created by by mathick(4) About Me : View Source, Show
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Try a sample problem!

3 + 5
Problem:
3 + +5
3 + (-5)
3 - (+5)
3 - -5
-3 + (-5)
-3 - -5
If you see two signs next to each other,
change them to a single sign:
++ changes to +
+- changes to -
-+ changes to -
-- changes to +
3 + 5
3 - 5
3 - 5
3 + 5
-3 - 5
-3 + 5
Now there are just two signs.
(For example, 3-5 is really +3 - 5)

If the 2 signs are different,
the answer has the sign of the larger number.
(5 in this case, since 5 is larger than 3.)

If they're the same, the answer also has the same sign.
+
-
-
+
-
+
If the signs are different, subtract the two numbers.
If they're the same, add.
8
2
2
8
8
2
Final Answer:
+8
-2
-2
+8
-8
+2

Try one!
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