Look at the following examples to see how algebraic expressions can be used to represent word problems.

**Example 1**

Katie eats **a **cookies and her brother Freddie eats **5 **more than Katie.

We can write this as an algebraic expression:

Freddie eats **a + 5 **cookies.

**Example 2**

There are **x **number of sheep in a field and **y **number of cows.

The farmer doubles the number of sheep.

How many animals are there in the field now? Write this as an algebraic expression.

__Answer__

There are now **2x + y** animals in the field.

In the questions that follow, we're going to practise using algebra to express word problems.

Here is a list of some of the most important ways to express word problems using algebra. Have a read through and then we'll start on the questions.

Expression | Word Problem |
---|---|

a + 4 | 4 more than a |

a - 4 | 4 less than a |

4 - a | a less than 4 |

4a | 4 times a |

a/4 | a ÷ 4 or ¼ of a |

3a + 4 | 4 more than 3 times a |

a/2 - 6 | 6 less than half of a |