Any Which Way
The players agree on a target. A useful target is 10, but other numbers are fine.
Each player is dealt five cards from a deck without face cards. Players then find as many ways as they can to get the target, or get as close to the target as possible, using any combination of addition and subtraction with any of their cards.
Do this as a group activity where the whole group is given five cards to use to cooperatively come up with ways to achieve the total.