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Adding and subtracting negative numbers

This page was translated from German with AI. It has not been checked by a native speaker. Original page in German

In the morning it is \(-3\) °C. It gets 5 degrees warmer. How warm is it then? You calculate with jumps on the number line.
📄 Open worksheet (PDF, German)

The video

In the video we jump on the number line: with plus to the right, with minus to the left.

Subtitles are available in ten languages. Choose them at the bottom right of the video.

Contents of the video

  1. 0:00 Introduction
  2. 0:16 Plus: to the right
  3. 0:40 Minus: to the left
  4. 0:59 Adding and taking away negatives
  5. 1:40 Careful, mistake!
  6. 2:06 Try it yourself

The most important points

Plus and minus

Plus means to the right: \(-3 + 5 = 2\). Minus means to the left: \(2 - 5 = -3\).

Start at -3, 5 to the right: -3 + 5 = 2.
Start at \(-3\), 5 to the right: \(-3 + 5 = 2\).

Adding and taking away negative numbers

Plus minus becomes minus: \(4 + (-6) = 4 - 6 = -2\). Minus minus becomes plus: \(1 - (-3) = 1 + 3 = 4\). Taking away debts means: more money.

4 + (-6) = -2 and 1 - (-3) = 4.
\(4 + (-6) = -2\) and \(1 - (-3) = 4\).
-4 - 3: another 3 to the left, so -7.
\(-4 - 3\): another 3 to the left, so \(-7\).

The worksheet

Here you can see the worksheet for the video (in German). First it explains everything again, then there are practice tasks at three levels. You can also open it as a PDF and print it.

📄 Open worksheet (PDF, German)

The worksheet – Page 1
Page 1/4
The worksheet – Page 2
Page 2/4
The worksheet – Page 3
Page 3/4
Show the worksheet solutions
The worksheet – Page 4
Page 4/4

Try it yourself

Task

Calculate: a) \(-2 + 7\) b) \(3 - 8\) c) \(-5 - (-2)\)

Show solution

a) \(5\) b) \(-5\) c) \(-5 + 2 = -3\)

Keep learning with a language model

Du bist meine Mathe-Lehrkraft. Ich lerne Deutsch als Zweitsprache. Unser Thema: rationale Zahlen addieren und subtrahieren (Zahlengerade, plus und minus negative Zahlen, Klammern auflösen). Stelle mir nacheinander fünf kurze Aufgaben. Warte immer auf meine Antwort. Sag mir dann, ob sie richtig ist, und erkläre kurz, warum. Benutze einfache deutsche Sätze.

How this was made: The idea, structure and examples of the series are mine. I made them with the help of AI: a language model (LLM) built the slides of the video following my instructions. The voice was generated with Qwen3-TTS, modelled on my own voice.

The subtitles, the translations, the worksheet and this page were also made with the help of AI. The translations have not been checked by native speakers.

The videos, worksheets, texts and prompts in this series are licensed under CC BY 4.0: you may use, change and share them if you name the source.