Before we compare fractions, we try to get them to have the same **denominators**.

We do this by using** lowest common multiples**.

Suppose we wish to compare:

7 | and | 4 |

9 | 6 |

We look for the smallest number that 9 and 6 go into.

This will be 18, so we change both fractions into 18ths.

We multiply the numerator and denominator of 7/9 by 2:

7 | = | 14 |

9 | 18 |

We multiply the numerator and the denominator of 4/6 by 3:

4 | = | 12 |

6 | 18 |

So we now have

14 | and | 12 |

18 | 18 |

14 | > | 12 |

18 | 18 |

7 | > | 4 |

9 | 6 |

**Example**

Which is bigger?

12 | or | 11 |

8 | 6 |

**Answer**

The lowest common multiple of 8 and 6 is 24, because 3 × 8 = 24 and 4 × 6 = 24.

We multiply the numerator and the denominator of 12/8 by 3:

12 | = | 36 |

8 | 24 |

We multiply the numerator and the denominator of 11/6 by 4:

11 | = | 44 |

6 | 24 |

44 |
> |
36 |

24 | 24 |

11 | is bigger |

6 |

Let's move on to the questions now.