# Equations and Expressions: Level 3

The key idea of equations and expressions at level 3 is that equations show relationships of equality between parts on either side of the equal sign.

At this level students need to understand that the equals sign means “equal to” or “the same as.” Both sides of the equals sign represent the same quantity. A common misunderstanding among students is that the equals sign indicates that a number operation needs to be performed, as when using a calculator. Working with equations such as 4 x 5 = 10 + 6 + 4 helps develop the understanding that the same quantity is shown on both sides of the equals sign, rather than one side showing an instruction for an operation and the other the answer.

Students need to be able to record formal equations to represent their solutions to addition, subtraction, multiplication and division problems.  Formal written algorithms for multi-digit addition and subtraction should be introduced after students have the nested place value knowledge required to understand them.

This key idea develops from the key idea of equations and expressions at level 2 where number operations and strategies to solve number operations are recorded using words, numbers, diagrams and symbols.

This key idea is extended to the key idea of equations and expressions at level 4 that that linear relationships between variables can be represented by a linear equation.