Evaluating Algebraic Expressions | DigiTransact Mastermind

What evaluate expressions means

You use given values to work out the value of an algebraic expression. This helps you check your answers in algebra and build confidence for later topics such as equations.

What you will practise

Replace letters with the correct numbers.
Work out powers before adding or subtracting.
Follow order of operations carefully.
Find the value of simple expressions from a rule.

Before you start

You should be comfortable with basic arithmetic, including multiplication, division, addition and subtraction. You also need to know what a variable and a power mean.

Not confident yet? Work through Solve two-step equations first.

Worked example

One question from this skill's own question bank, shown with its full working.

Question

If a = 3, what is 4a + 2?

Answer: 14

Working: Substitute a = 3: 4 × 3 + 2 = 12 + 2 = 14.

Common mistakes to avoid

Leaving the letter in the expression instead of using the given value.
Doing addition before multiplication or powers. Follow the correct order.
Changing the sign when substituting a negative value. Keep brackets clear.
Forgetting to square the number when the expression includes an exponent.

Curriculum and exam alignment

Ghana GES Basic 7 to 9 syllabusBECE

In Junior High School, this usually appears in early algebra work, after learners have met variables and simple number rules. It supports later work on equations and is useful for BECE preparation.

Curriculum notes are a general guide to where this work normally sits. Always check the syllabus your school or examination body is currently using.