Beyond Rankers Academy
Building Minds, Not Just Rankers
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Beyond Rankers Academy
Building Minds, Not Just Rankers
Main site →
The number line now stretches below zero too — into negative numbers. A temperature of −5°C, a lift going 3 floors below ground, a debt of ₹200: integers describe all of these.
Zero sits in the middle. Positive numbers go right, negative numbers go left.
… −4 −3 −2 −1 0 1 2 3 4 …
On a number line, a number further RIGHT is always bigger — even if it looks smaller ignoring the sign.
Trap: −10 is SMALLER than −2, even though 10 is bigger than 2 — the extra negative pushes it further left, and further left always means smaller.
Same sign? Add the numbers and keep the sign. Different signs? Subtract the smaller from the bigger, and keep the sign of the bigger one.
Subtracting an integer is the same as adding its opposite: 5 − (−3) becomes 5 + 3.
🔑 The flip rule
To subtract an integer, change its sign and add instead: a − b = a + (−b). So 5 − (−3) = 5 + 3 = 8, and 5 − 3 = 5 + (−3) = 2.
12 IMO-style questions on comparing, adding and subtracting integers. 🍀