Negative Numbers

Understanding Negative Numbers

• Negative numbers are numbers that are less than zero and are usually represented with a minus (-) sign in front.
• Think of them as being on the left side of zero on a number line, while positive numbers are on the right.

Adding and Subtracting Negative Numbers

• When you add a negative number, it’s the same as subtracting a positive number.
  • For example, 5 + (-3) = 5 - 3 = 2.
• When you subtract a negative number, it’s like adding a positive number.
  • For example, 5 - (-3) = 5 + 3 = 8.

Multiplying and Dividing Negative Numbers

• The product or quotient of two negative numbers is a positive number.
  • For example, -2 * -3 = 6 and -6 / -3 = 2.
• The product or quotient of one positive number and one negative number is a negative number.
  • For example, 2 * -3 = -6 and 6 / -3 = -2.

Absolute Value of Negative Numbers

• The absolute value of a negative number is the number without its negative sign. It represents the distance of the number from zero on the number line.

  • For instance, the absolute value of -5 is written as

    -5

    and equals 5.

Real-World Applications

• Negative numbers are used in real life situations such as describing temperatures below zero, indicating debt, or measuring elevations below sea level.

Practice Problems

• Problem: Subtract -4 from 7.
  • Solution: 7 - (-4) = 7 + 4 = 11
• Problem: Multiply -3 by -2.
  • Solution: -3 * -2 = 6
• Problem: What is the absolute value of -9?

  • Solution:

    -9

    = 9

Understanding and Revising

• Try to visualise negative numbers on a number line to better understand how they work.
• Work on numerous practice problems to get comfortable dealing with negative numbers in different mathematical operations.
• Don’t forget, two ‘negatives’ make a ‘positive’ when multiplying or dividing. It’s often said that “a negative times a negative gives a positive”.