Leaving Certificate Mathematics Definitions Practice Test 2026 – The Comprehensive All-in-One Guide for Exam Success!

A fixed number is called a constant. In algebra, a variable is a symbol that can take different values, while a constant has the same value no matter what the variable does. For example, in an expression like 4x + 7, the 4 is a coefficient (the number multiplying the variable), and the 7 is a constant—the part that stays the same regardless of x. Even well-known numbers like π are constants because their value doesn’t change. A substitute isn’t the standard term for a fixed value in an expression, so it doesn’t describe this concept.