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Negative Numbers

Grades 5-7 · Concept Explainer

Key Points

  • ✓Negative numbers are less than zero.
  • ✓They are written with a minus sign (-).
  • ✓They are located to the left of zero on a number line.
  • ✓The further left on the number line, the smaller the number.
  • ✓Negative numbers can represent real-world situations like temperature or debt.

Negative numbers are numbers less than zero. They are written with a minus sign (-) in front of them. Think of a number line: zero is in the middle, positive numbers are to the right, and negative numbers are to the left. The further left you go, the smaller the number gets. Negative numbers are useful for representing things like temperatures below zero, debts, or elevations below sea level. Understanding them helps us solve problems in everyday life and in more advanced math.

Worked Example

The temperature outside is 5 degrees Celsius. Overnight, it drops by 8 degrees. What is the new temperature?

  1. Step 1: Start with the initial temperature: 5 degrees.
  2. Step 2: Subtract the temperature drop: 5 - 8.
  3. Step 3: Since we are subtracting a larger number, the answer will be negative. 8 - 5 = 3.
  4. Step 4: Add the negative sign: -3.

Answer: The new temperature is -3 degrees Celsius.

Try It Yourself

1. What number is 3 less than 1?

2. A submarine is 200 feet below sea level. It descends another 150 feet. What is its new depth?

3. You have $50 in your bank account. You spend $75. What is your account balance?

Watch Out For These Mistakes

  • Thinking that -5 is greater than -2 (it's smaller).
  • Forgetting the minus sign when writing a negative number.
  • Confusing negative numbers with positive numbers when adding or subtracting.