The voting systems used in South Dakota are optical scan and paper ballots.
Optical Scan: With this system, you will receive a card or sheet of paper, which you take over to a private table or booth. The card has the names of the various candidates and ballot measures printed on it. With a pen or pencil you fill in a little box or circle or the space between two arrows. When you are finished filling out all the cards, you may bring the cards over to a ballot box, where poll workers will show you how to put the cards in the box. Or in some places, you may feed the completed cards or papers into a computer device that checks your card or paper right there at the polling place to make sure you have voted the way you want to and counts the votes.
Paper Ballots: Paper ballots are one of the oldest ways of voting in America. They are still used in a few places on Election Day. When you come to the polling place, you will get a paper ballot from the poll worker. You take it to the voting booth, and use a pen or pencil to mark a box next to your candidate and issue choices. You then drop the marked ballot into a sealed ballot box.
You can learn more about voting systems by checking out the Elections Assistance Commission's (EAC)