The atonement mitzvah
It is a mitzvah to perform atonement before Yom Kippur, the atonement ceremony can be performed using a chicken or by donating money to a charity on Yom Kippur eve.
The mitzvah period
To begin with, the atonement mitzvah should be performed in the ten days of repentance – the days between Rosh Hashana and Yom Kippur.
How much to give per person?
In Jewish law, it is customary to give the equivalent of a chicken for each person in the household. A pregnant woman makes a donation for her fetus as well.
In practice, there are different customs, from those who give $18 per person (HAI in gematria), and those who give 10 times HAI, a sum of $180
It is right for every person to act according to their family’s tradition, and anyone giving charity is rewarded from above.
Atonement prayers said for another person
If the prayer is said for another person, one should say "this is your substitute, your compensation, your atonement".
Family member who isn’t present at the moment?
The atonement mitzvah can be performed for someone who isn’t present.
In such a case, one should say "the substitute of [person’s name]".
A person who has not observed the mitzvah in time
A person who has not observed the mitzvah on Yom Kippur eve should complete the atonement custom in Hohsana Rabba – the seventh day of Sukkot.
Since this day is considered to be a small Yom Kippur.
Giving atonement from tithe money (ma’aser)
Tithe money should not be used to observe the bulk of the atonement mitzvah.
But the addition beyond the minimum required can certainly be taken from tithe money.