It was Beth's birthday part coming up next week, and Beth and her mom sat down at the table to write invitations to all her friends.  She had twenty to write, so that is why they both were doing it together.  Beth had a pile in front of her, pretty cards, and a big ink pen to write with. She started , and the first thing she did was put her name, the time of the party, and where the party was, on each card.  Then she wrote, " Please come! Love, Beth" on each one.   Her mother then put them all in envelopes and stuck a stamp on the envelopes.  Lastly, she wrote out the addresses on all the invitations.  Beth helped her mother gather the envelopes together, and they drove to the post office to mail them. Beth was excited when they were all mailed, and thanked her mother for helping her with the party invitations.
Why were invitations sent out?