⚡ Key Concepts & Memory Points
📏 THE NUMBER LINE — Always your best friend!
−5
−4
−3
−2
−1
0
+1
+2
+3
+4
+5
← Negative (Left) | Positive (Right) →
✏️ Memory Point #1 — ADDITION
SAME sign → ADD, KEEP the sign
(+5) + (+3) = +8 | (−5) + (−3) = −8
✏️ Memory Point #2 — SUBTRACTION
SUBTRACTING = Adding the OPPOSITE
(+5) − (+3) = (+5) + (−3) = +2
(+5) − (−3) = (+5) + (+3) = +8
✏️ Memory Point #3 — DIFFERENT SIGNS
DIFFERENT signs → SUBTRACT, KEEP bigger sign
(+7) + (−3) = +(7−3) = +4
(−7) + (+3) = −(7−3) = −4
🔑 THE GOLDEN RULE — Double Negative
− (−) = + ← Two negatives make a POSITIVE!
Example: 5 − (−3) = 5 + 3 = 8
➕ Pos + Pos
(+5) + (+3) = +8
Move RIGHT on number line
➖ Neg + Neg
(−5) + (−3) = −8
Move LEFT on number line
🔀 Pos + Neg
(+7) + (−3) = +4
Bigger wins! 7 > 3 → positive
🔀 Neg + Pos
(−7) + (+3) = −4
Bigger wins! 7 > 3 → negative
📖 Worked Examples
✅ Example A — Subtraction Trick
Solve: (+5) − (−7)
→ Step 1: Change subtraction to addition: (+5) + (+7)
→ Step 2: Same signs → Add and keep sign
→ Answer: +12 ✓
✅ Example B — Different Signs
Solve: (−5) + (+7)
→ Step 1: Different signs → subtract smaller from bigger
→ Step 2: 7 − 5 = 2. Who's bigger? +7 → positive wins
→ Answer: +2 ✓
✅ Example C — Tricky Double Negative
Solve: (−5) − (−3)
→ Step 1: − (−3) becomes + (+3)
→ Step 2: (−5) + (+3) → Different signs
→ Step 3: 5 − 3 = 2. −5 is bigger → negative wins
→ Answer: −2 ✓
Keep practicing! 🌟 You got this.