# Front end estimating

Front end estimating is rounding the first significant number on any calculation as a rough estimate.

Sometimes the front end is more important.

**Example 1**

Estimate the following sum:

`4026+398+42`

Adding `4026+398+42` is tricky.

But adding `4000+400+40` is easy.

`4000` | |

`+` | `400` |

`+` | `40` |

`4440` |

**NOTE:**

The real answer is `4466` and so you can see that `4440` is a worthy estimate.