Call it a hunch, but if you need, say, 24 napkins for the party, you probably don’t want 24 people to bring one napkin each. If your sign up quantities don’t look the way you expected, there is a simple fix.
When you enter the "# Wanted" for a slot, you are choosing the number of people you want to sign up for the item. For example, if you want one person to bring 24 napkins, your slot should read "24 pack of napkins" with a "# Wanted" of one selected. If you choose a "# Wanted" of 24, you are actually allowing 24 people to sign up for that slot.
To edit your slots, log in and go to the "Created" tab from your account Sign Ups page. Click on the sign up. At the top of the page, click "Edit Content" from the Admin’s Toolbar. Go to Step 4: Slots. Click "Edit" next to the slot you need to change. Then, click "Edit Selected" at the top of the column. Here you can edit the slot info and click "Update" to save the changes. If you already have people signed up on your sign up, proceed with caution.
In that scenario, you can simply reduce the "# Wanted" to three. Additionally, you can contact those individuals to work out the details. Once you determine who will remain on the sign up slot, you can remove the other two names and then reduce the "# Wanted" down to one.