Number Line

A number line is a visual tool used to represent all types of numbers, including integers, fractions, and decimals.

• Integers: Numbers like −23, 0, 8
• Non-integers: Numbers like `3/5`, \[\sqrt{2}\],​ `5/2`

• The number line helps us visualise how to add and subtract numbers.
• Moving to the right on the number line represents positive movement (addition).
• Moving to the left represents negative movement (subtraction).
• (Remember: Starting Number + Movement = Target Number)

An unmarked number line (UNL) shows only zero (0), and you can visualise the addition or subtraction by imagining the scale of the numbers.
Example:
After moving right by 85 and left by 60, you land at +25.
so 85 + (−60) = 25

• Example 1: From 5 to 9
  If you start at 5 and want to move to 9, you need to move 4 steps forward (right).
  5 + 4 = 9 
  
  
• Example 2: From 9 to 3
  Starting at 9 and moving to 3 requires you to move 6 steps back (left).
  9−6=3 
  
  
• Example 3: From 3 to -2
  Starting at 3 and moving to -2 requires moving 5 steps back (left).
  3 + (−5) = −2 
  

• Right means increase, and left means decrease.

• Zero (0) separates positive and negative numbers.

• Positive numbers are greater than zero; negative numbers are less.

• Numbers get larger as you move right and smaller as you move left.