By sum you mean the sum of the area?

You can use `SUMIF()`

.

```
=SUMIF(B:B,1,C:C)
```

For instance will give you the sum of all the `codenb`

equal to `1`

.

`B:B`

is the column with the criteria (column `codenb`

);

`1`

is the `codenb`

that you're summing;

`C:C`

is the column containing the values to sum.

If you want to get a table with a summary of all the `codenb`

and the sum of each group of areas, then a PivotTable will be easiest/fastest.

- Insert a PivotTable on the table in a new sheet;
- Put (click + drag) column
`codenb`

in 'Row Labels' from the right pane;
- Put (click + drag) column
`area`

in 'Values' from the right pane;
- Make sure that the values are summarised by 'Sum'.