In Year 8 Mathematics, learning about variables is super important for changing simple algebraic expressions.

1. What are Variables?

   • A variable is a letter, like $x$ or $y$, that stands for a number we don't know yet.

2. What are Expressions?

   • Simple algebraic expressions combine constants (fixed numbers) and variables. For example, $3x + 5$ is an expression.

3. How Do We Change Expressions?

   • We can create new expressions by replacing the variable with a number. For instance, if we say $x = 2$, then $3x + 5$ becomes $11$.
   • Variables help us show general ideas, like using formulas to find areas. For example, the formula $A = l \times w$ helps us calculate the area by multiplying length and width.

4. A Look at the Numbers:

   • In Sweden, about 75% of Year 8 students understood how to use variables well in tests taken in 2022.