Number Line

What Is a Number Line?

• A number line is a straight line with numbers placed at equal intervals.
• It works like a never-ending ruler that helps us see where numbers live.
• It is a visual tool used to count, compare, and solve math problems.

How a Number Line Works The direction you move on the line changes the value of the numbers:

• Moving to the Right: The numbers get bigger (Example: 2, 3, 4...). This is used for addition.
• Moving to the Left: The numbers get smaller (Example: 4, 3, 2...). This is used for subtraction.
• The Starting Point: Usually starts at 0, but a number line can start or end at any number.

Using a Number Line for Addition To add, we "jump" forward to the right:

• Start at the first number in your problem.
• Take as many jumps as the second number tells you.
• The number you land on is your Sum.
• Example (3 + 2): Start at 3, take 2 jumps right. You land on 5!

Using a Number Line for Subtraction To subtract, we "jump" backward to the left:

• Start at the first (bigger) number.
• Take as many jumps back as the second number tells you.
• The number you land on is your Difference.
• Example (7 - 3): Start at 7, take 3 jumps left. You land on 4!

Comparing Numbers A number line helps us see which numbers are greater or smaller:

• Numbers on the right are always greater than numbers on the left.
• It helps us understand "Before" and "After" (Example: 5 is before 6).

Why Do We Use Number Lines?

• It makes skip counting easier to see and do.
• It helps us understand the order of numbers.
• It is a great way to "see" the math instead of just doing it in our heads.

Lesson Summary

• A number line is a tool for counting and solving problems.
• Jump right to add and jump left to subtract.
• Numbers are always placed in order from smallest to largest.