Number Line
A line where numbers are placed in order at equal spacing to compare and add them.
Key idea
A line where numbers are placed in order at equal spacing to compare and add them.
In depth
A number line turns numbers into positions. Equal spacing means distance on the line equals difference in value, so adding moves you right and subtracting moves you left. Numbers to the right are always greater.
Worked example
To compute 3 + 4, start at 3 and take 4 steps right to land on 7.
Real-world uses
- Reading thermometers and bus timetables
- Marking distances on a map or a ruler
- Seeing which of two numbers is bigger
Common mistake
Uneven tick spacing. If the marks are not equally spaced, the picture lies about the sizes.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Number Line?
A line where numbers are placed in order at equal spacing to compare and add them. It is a topic at the beginner level in Arithmetic & Number Sense.
Where is Number Line used in real life?
Real-world examples: Reading thermometers and bus timetables; Marking distances on a map or a ruler; Seeing which of two numbers is bigger.
What should I learn before Number Line?
Make sure you are comfortable with Place Value, the previous topic in Arithmetic & Number Sense.
What is a common mistake with Number Line?
Uneven tick spacing. If the marks are not equally spaced, the picture lies about the sizes.
How can I practise Number Line?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Number Line?
Move on to Comparing Numbers next.
Related beginner topics in Arithmetic & Number Sense
- Counting & Cardinality – Assigning one number word to each object to find how many there are.
- Place Value – The value of a digit depends on its position: ones, tens, hundreds and so on.
- Comparing Numbers – Use <, > and = to say which number is smaller, larger or equal.
- Ordering Numbers – Arranging numbers from least to greatest or the reverse.
- Even and Odd Numbers – Even numbers divide by 2 with no remainder; odd numbers leave remainder 1.
- Skip Counting – Counting forward by a fixed step such as 2s, 5s or 10s; the root of multiplication.