multiplied with another and give the result in another?

how do I want a field operations have multiplied with another and give the result in another?

Loads of info there mate.
Maybe some fields from your tables might give us something to work with, otherwise if you use the * in your sql, it will multiply things for you.

Hi,
use Before record added/updated events on the Events tab to calculate field value.

Here is a sample:

$values["field3"] = $values["field1"]+$values["field2"];

Seeing your reply Jane makes it abit more clearer.
You could have something like
Three fields named field_1, field_2 and field_3.
You could do something like
select field_1field_2field_3 as total