AR014 · Arithmetic operations · Classes 6–8
Negative number arithmetic
Adding a positive number moves right on the number line; adding a negative number moves left. Subtracting a number is the same as adding its opposite.
−5 + 8Negative number arithmetic
📐 Formula
a − b = a + (−b); a + (−b) moves left by b
✏️ Worked example
−5 + 8 = 3: start at −5 and move 8 steps right.
🌍 Where it is used
Temperatures, bank balances, lifts going below ground.
❓ Quick check
−4 − 6 = ?
🏋️ Practice
Easy−3 + 7 = ?
Answer: 4
Medium5 − (−4) = ?
Answer: 9
ChallengeA diver at −12 m rises 5 m. New depth?
Answer: −7 m