When voters entered polling places across Washington Tuesday, they had two options: electronic and paper voting.

In paper form, voters filled out bubbles with pencil on a printed ballot. They then fed those ballots through an optical reader similar to a Scantron, which counted the votes and recorded them into a physical electronic cartridge.

Those who opted for electronic ballots used a touch screen to vote. The resuts were also stored in an electronic cartridge similar to those from the paper ballot readers. Electronic voting machines also printed a receipt to verify election results.

Cartridges holding data from both electronic and paper ballots were shipped downtown for final tabulation Tuesday night.

For the first time, the D.C. Board of Elections this year gave each precinct two electronic voting machines, according to BOE spokesperson Tamara Robinson.

D.C. electon officials blamed the delay in releasing election results on poor training of poll workers on the use of the electronic voting machines.

Voters in Washington have had the choice between paper and electronic voting systems since 2004.

D.C. also allowed early voting for two weeks, which ended Saturday.

The D.C. Board of Elections divides Washington into 143 precincts, each with its its own polling place. Each precinct houses between 1,000 to 10,000 registered Washingtonians, or between 400 and 5,000 Democrats. The borders of more densely populated precincts are typically smaller. They’re designed with the goal of being walkable from any one part of the precinct to the polling station, and they can change over time.

Julie Zauzmer and Mike DeBonis contributed to this report.