Use of letters to represent numbers - JSS1 Mathematics Lesson Note

In mathematics, letters can be used to represent numbers. This is often done in algebra where letters stand in for unknown values or variables. For example:

Example 1: Let’s say we have the equation 

𝑥+5 = 10

Here, 

𝑥 is a letter representing a number. To find out what number

𝑥 represents, we can solve the equation. Subtracting 5 from both sides, we get:

𝑥= 5

Example 2: In the equation 

3𝑦= 12, the letter 𝑦 represents a number. Dividing both sides by 3, we find:

𝑦= 4

These letters (or variables) make it easier to write general rules or formulas that can be used for many different numbers.