Adding and subtracting negative numbers | Pre-Algebra | Khan Academy

TL;DR

Learn how to add and subtract negative numbers by visualizing them on a number line.

Transcript

Let's have some practice adding and subtracting negative numbers. So the first example I want to look at is 2 minus 3. So right now I'm just subtracting a positive number from another positive number, but you might already see that I'm subtracting a larger number from a smaller number. So I'm probably, or I will, definitely end up with a negative n... Read More

Key Insights

• #️⃣ Subtracting a positive number from another positive number results in a negative number.
• #️⃣ Subtracting a negative number from a negative number leads to a positive number.
• #️⃣ Adding a positive number to a negative number results in a positive number.
• #️⃣ Subtracting a negative number from a negative number is the same as adding a positive number.

Questions & Answers

Q: How can I subtract a positive number from another positive number?

To subtract a positive number from another positive number, start at the first number on the number line and move to the left by the second number. The ending point will be a negative number.

Q: What happens when I subtract a negative number from a negative number?

Subtracting a negative number from a negative number is equivalent to adding a positive number. Start at the first number on the number line and move to the right by the second number. The ending point will be a positive number.

Q: How do I add a positive number to a negative number?

When adding a positive number to a negative number, start at the negative number on the number line and move to the right by the positive number. The ending point will be a positive number.

Q: What is the result of subtracting a negative number from a negative number?

Subtracting a negative number from a negative number is the same as adding a positive number. Start at the first number on the number line and move to the right by the second number. The ending point will be a positive number.

Summary & Key Takeaways

• The video demonstrates how to subtract a positive number from another positive number, resulting in a negative number.

• It also shows how to subtract a negative number from a negative number, resulting in a positive number.

• Additionally, the video explains how to add a positive number to a negative number and subtract a negative number from a negative number, both resulting in a positive number.