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Understanding Integers: A Mini Course

Mar 19, 2025

Math with Mr. J: Mini Course on Integers

Overview

  • Topics covered:
    • What integers are
    • Comparing and ordering integers
    • Adding, subtracting, multiplying, and dividing integers
  • Audience: New learners or those reviewing integers.

1. What are Integers?

  • Definition: Integers are whole numbers without fractional or decimal parts.
  • Includes:
    • Positive numbers (e.g., 1, 2, 3, ...)
    • Negative numbers (e.g., -1, -2, -3, ...)
    • Zero (0)

Number Line Illustration

  • Positive Integers: Counting up from zero (1, 2, 3, ...)
  • Negative Integers: Counting down from zero (-1, -2, -3, ...)
  • Zero: Separates positive and negative integers.

Examples of Integers

  • Positive: 8, 37, 194
  • Negative: -9, -5, -72
  • Zero: 0

Non-Integers Examples

  • 1/2, 4.38, 6.3, 0.45 (all contain fractions or decimals)

Integer Check

  • Yes/No: Check if given numbers are integers.
    • 42: Yes
    • -8: Yes
    • -8.5: No
    • 3 1/3: No
    • 0: Yes
    • -7: Yes
    • 1/12: No
    • 996: Yes
    • 10.75: No

2. Comparing and Ordering Integers

Comparing Integers

  • Visualize with a number line:
    • Right is greater: e.g., -1 is greater than -2.
    • Left is smaller: e.g., 3 is greater than -5.

Examples

  1. -1 vs -2: -1 is greater.
  2. -5 vs 3: 3 is greater.
  3. 0 vs -4: 0 is greater.
  4. 95 vs 6: 95 is less.
  5. -14 vs 11: -14 is less.
  6. -27 vs -29: -27 is greater.

Ordering Integers

  • Organizing from least to greatest or vice versa using number lines.

Least to Greatest Example

  • Order: -5, -2, -1, 0, 4

Greatest to Least Example

  • Order: 5, 3, 1, -2, -3

3. Operations with Integers

Addition

  1. Example 1: 12 + (-7)
    • Different signs: Subtract absolute values.
    • Answer: 5
  2. Example 2: 8 + (-10)
    • Same signs: Add absolute values.
    • Answer: -18

Subtraction

  1. Example 1: 5 - (-9)
    • Convert to addition: 5 + 9 = 14
  2. Example 2: -3 - 20
    • Add opposite: -3 + (-20) = -23

Multiplication

  1. Example 1: -7 * 4
    • Different signs: Result is negative (Answer: -28)
  2. Example 2: -10 * -6
    • Same signs: Result is positive (Answer: 60)

Division

  1. Example 1: -48 / -8
    • Same signs: Result is positive (Answer: 6)
  2. Example 2: 36 / -4
    • Different signs: Result is negative (Answer: -9)

Conclusion

  • This mini-course covers the fundamentals of working with integers.
  • Important concepts include definitions, comparisons, orderings, and performing operations.
  • Mastery of these concepts is essential for further mathematical understanding.