What are the rules for adding and subtracting integers?

Adding and Subtracting Integers: The Rules

When you add or subtract integers, keep these key rules in mind:

Adding Integers

• Same signs: Add the absolute values, keep the common sign.
• Example: +3 + (+2) = +5 or -4 + (-3) = -7.
• Different signs: Subtract the smaller absolute value from the larger one. Use the sign of the number with the larger absolute value.
• Example: -6 + 2 = -4 (since 6 > 2, keep the negative sign).

Subtracting Integers

• Change to addition: Subtraction is the same as adding the opposite.
• a - b = a + (-b)
• Example: 3 - (-5) = 3 + 5 = 8

Short Example
Suppose you have -7 - (+4).

1. Rewrite as addition: -7 + (-4)
2. Same signs? Yes, both negative.
3. Add absolute values: 7 + 4 = 11
4. Keep the negative sign: -11

---

Takeaway:

• Add like signs, subtract unlike signs; always keep the proper sign.
• Change subtraction to addition by adding the opposite integer.