--- title: "Adding and Subtracting Negative Numbers" description: "Add and subtract with negative integers, reading each move as a direction on the number line, and settle what subtracting a negative does." canonical: https://lightmysky.com/learn/mathematics/adding-and-subtracting-negative-numbers-mt_qX7X7uMzsY source: https://lightmysky.com/learn/mathematics/adding-and-subtracting-negative-numbers-mt_qX7X7uMzsY.md retrieved: 2026-09-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Adding and Subtracting Negative Numbers Add and subtract with negative integers, reading each move as a direction on the number line, and settle what subtracting a negative does. Subject: Mathematics · Area: Addition & Subtraction · Ages 12 to 13 Page: https://lightmysky.com/learn/mathematics/adding-and-subtracting-negative-numbers-mt_qX7X7uMzsY ## Ready when they can - Work out sums like -7 + 3 and 4 - 9 without a calculator and say which way the answer lies from zero - Explain why subtracting a negative moves the same way as adding a positive, using a context such as debt or temperature - Order a mixed list of positive and negative numbers and find the distance between two of them ## Lesson: Walking the line with negatives Negative numbers count things below zero: debt, basement floors, frost. Adding a positive moves right on the number line, adding a negative moves left. For -7 + 3, start at -7 and step 3 places right to land on -4. *(drawing: Start at -7, hop 3 right, land on -4.)* **Example.** Subtracting flips direction, and subtracting a negative flips twice. That is why 5 - (-3) equals 5 + 3, which is 8. Owing a debt and having it cancelled feels like gaining money. The gap from -4 to 6 is 6 minus -4, which is 10. **Tip.** Same signs combine: keep the sign and add the sizes, so -2 + (-5) is -7. Different signs compete: keep the sign of the bigger size and subtract. Before computing, guess the sign. That one-second check catches most slips. To order mixed numbers, put every negative below every positive, then sort and pick the middle. **Recap.** Walk the line: plus faces right, minus faces left, and taking away a debt moves you right. ## Practice 14 questions on this page, each with its working shown. ## Needs first - [Negative numbers in context](https://lightmysky.com/learn/mathematics/negative-numbers-in-context-mt_1KkvzwYxbR) - [Positive and Negative Numbers](https://lightmysky.com/learn/mathematics/positive-and-negative-numbers-mt_9QzSnn8m80) ## Opens up - [Expanding Double Brackets](https://lightmysky.com/learn/mathematics/expanding-double-brackets-mt_KhS7K1Mgrw)