# Expressions

Equations, terms, expressions and identities are things that get mixed up all the time.

A term is something made up of numbers, letters or both and is found between operators such as add, divide, multiply and subtract or the equals sign. Examples of terms include x, 3y, xyz and 7. So when we say, collect the like terms, we are saying collect the numbers together, collect all the terms that have x in together etc. It is important to note that x terms and x squared are not like terms.

An expression is made up of several terms and does not include an equals sign. Examples of an expression might be 3x + 2, 6 - 7y etc. If you have an equals sign, you have an expression on the left hand side of it and another on the right.

An equation is something that contains an equals sign. A=B would be an equation where A and B are expressions.

An identity is denoted with a three bar equals sign. It means that something is always true, no matter what values are substituted for the unknown quantities. A simple example would be that 3x + 2 = 5x is true when x=1 and so this is an equation. 3x + 2x = 5x is always true, no matter what the value of x, so this is an identity.

## Changing the subject

Change the subject of the equation.

## Derive an expression

Derive an algebraic expression to solve problems.

## Expanding single brackets

Expanding single brackets and two sets of single brackets.

## Derivation of Expressions

GCSE Exam questions on derivation of expressions

## Formulating Expressions

Formulating expressions from real life scenarios.

## Formulate expressions for cuboids

Find the length of the edges, the surface area and the volume of a cuboid.

## Video on formulating expressions

A video demonstrating how to formulate an expression for perimeter of an oblong.

## Cuboids help sheets

A help sheet explaining how to calculate the length of edges, surface area and volume of a cuboid using the FOIL method.

## Algebra from the beginning

A video showing algebra from ___ + 7=10 to 7p + 4 = 32.

## Unknowns on both sides

A video showing algebra where the same unknown exists on both sides of the equation.

## Video on basics of algebra

A video looking at the meaning of words such as co-effiecent, expressions and the looking how to solve equations. Be warned: this is a large video.

## GCSE questions on algrebraic fractions

GCSE questions on algrebraic fractions. Also includes the examiners comments and the mark scheme.

## Substitute into an expression

Substitute a value of x into 22 different expressions that build up as you move further from the centre.

## PowerPoint answers to algebraic expressions sheet

Provides a model for the answers given to the questions from the algebraic expressions sheet. The original question sheet can be found here.

## Video on how to find expressions on a cuboid

Video on how to find expressions for the length of the edges, the surface area and the volume of a cuboid. This involves finding the product of a number and a binomial, two binomials and three binomials.

## Find expressions on a cuboid

Find expressions for the length of the edges, the surface area and the volume of a cuboid. This involves finding the product of a number and a binomial, two binomials and three binomials.

## Video to find calculations to do with cuboids

Find expressions for the length of the edges, the surface area and the volume of a cuboid.

## Problems involving expanding brackets

Various problems whose solution involves expanding brackets.

## PowerPoint on expanding brackets

Questions on basic expansion of brackets. One of the slides includes a video. Answers are included within the presentation.

## Expanding two and three binomials

Practice on expanding two binomial expressions and the three binomial expressions.

## Expanding brackets practice

Practice on expanding brackets.

## Video on simplifying expressions

Video on simplifying basic algebraic expressions.

## Using the grid method for algebra

Using the grid method for algebra

## Grid Investigation

Grid investigation providing templates for different letters and several grids with grid sizes 12, 10 and 9 so students can investigate the difference in the results that different grid sizes provide. Many more grids can be found here.

## Grouping like terms

Grouping like terms beginning with shapes and working towards algebra with different powers.

## Forming Expressions 1

Use the available information to form equations and expressions to help you to solve problems.

## Forming Expressions 2

Use the available information to form equations and expressions to help you to solve problems.

## Forming Expressions 3

Use the available information to form equations and expressions to help you to solve problems.