Adding and Subtracting Negative Numbers

Feedback: Not quite! Starting at $–5^\circ\text{F}$, adding $12^\circ\text{F}$ gives $–5 + 12 = 7^\circ\text{F}$.

Feedback: Not quite! First, simplify –7 – (–4). Subtracting –4 is the same as adding 4, so –7 + 4 = –3. Then, –3 + (–2) becomes –3 – 2 = –5.

Feedback: Not quite! First, simplify –12 + (–8), which gives you –20. Then, subtracting –15 is the same as adding 15. So, –20 + 15 = –5.

Feedback: Not quite! Owing £20 means starting at $–20$. Paying back £8 is adding £8: –20 + 8 = –12, so you still owe £12.

Feedback: Not quite! First, simplify –14 + 5, which gives –9. Next, simplify –10 – 7, which gives –17. Subtracting –17 is the same as adding 17. So, –9 + 17 = 8.

Feedback: Not quite! Starting at –120, ascending 50 is adding: –120 + 50 = -70. Descending 30 is subtracting: –70 – 30 = –100.