Edexcel GCSE Foundation Maths: Writing Expressions

Introduction

In mathematics, an expression is a combination of numbers, variables, and operations. Writing expressions is a crucial skill in algebra and allows us to represent mathematical relationships concisely. This tutorial will guide you through the basics of writing expressions, covering the fundamental concepts and providing examples.

Key Concepts

• Variables: Letters used to represent unknown quantities or values that can change.
• Constants: Numbers that have a fixed value.
• Operations: Mathematical actions such as addition, subtraction, multiplication, and division.

Writing Expressions

To write an expression, follow these steps:

1. Identify the variables and constants: Determine the quantities involved in the problem.
2. Represent variables with letters: Choose appropriate letters to represent the unknown quantities.
3. Use operations to combine variables and constants: Apply the appropriate operations based on the problem's context.

Examples

1. Express the sum of a number and 5.

• Variables: Let 'x' represent the number.
• Constants: 5
• Operation: Addition
• Expression: x + 5

2. Express the product of 3 and a number decreased by 2.

• Variables: Let 'y' represent the number.
• Constants: 3 and 2
• Operations: Multiplication and subtraction
• Expression: 3(y - 2)

3. Express the area of a rectangle with length 'l' and width 'w'.

• Variables: l (length) and w (width)
• Operation: Multiplication
• Expression: l * w

Practice Problems

1. Express the difference between twice a number and 7.
2. Express the cost of buying 'n' apples at 50p each.
3. Express the perimeter of a square with side length 's'.

Conclusion

Writing expressions is a fundamental skill in mathematics. By understanding the key concepts and following the steps outlined in this tutorial, you can confidently represent mathematical relationships in a concise and efficient way. Remember to practice regularly to strengthen your understanding and develop fluency in writing expressions.