A team's points in a treasure hunt change round by round: −15, then +22, then −9, then +5. The team starts at 0. What are its points at the end, and is that above or below the start?

Subtraction of integers is just adding the **opposite**: a − b = a + (−b). So 5 − 8 = 5 + (−8) = −3. And 5 − (−8) = 5 + 8 = 13. The 'minus minus' that looks confusing in symbols is simply: subtracting a negative is the same as adding its positive twin. Always rewrite subtraction as addition of the opposite — it removes every sign-error trap.