What is a variable in maths? Simple Definition and Examples

Definition

A variable is a letter that stands for a number that can change or is unknown.

Example

In 2n + 1, n could be 3, giving 7.

Tip

Write 3x for 3 × x.

Practise it

Play: Equation Balance
Worksheets: Evaluating algebraic expressions (Grade 6)
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Quick check: try these

Work each one out on paper, then tap the question to see the answer.

Find 7x + 8 when x = 3:
Answer: 29
Find 6x + 11 when x = 3:
Answer: 29
Find 2x + 8 when x = 9:
Answer: 26
Find 4x + 8 when x = 3:
Answer: 20

Learn it in depth

Variable is part of Algebraic Expressions for Class 7: notes, formulas, solved examples with every step, common mistakes and ten practice questions with answers. Want a teacher to go through it with you? See Class 7 maths tuition.

Related words

Equation

FAQ

Variable: questions

What is a variable in maths?

A variable is a letter that stands for a number that can change or is unknown. In 2n + 1, n could be 3, giving 7.

What is a common mistake with variable?

Write 3x for 3 × x.

Where do students learn variable?

Algebraic Expressions is usually taught in Class 7, and the ideas come back in later classes. Chapter names and order differ by board and textbook, so follow your own textbook. We have a full page with notes, solved examples and practice questions.

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Profit and loss (Grade 7): Finding profit or loss as a percentage of the cost price, and the selling price after a gain or loss. Open the practice page or print a worksheet.

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