1÷x=1 (Undivided)

1÷x=1 (Undivided) is a follow-up of the band's arithmetic-themed album series.^[2] In April, Wanna One announced that the members will split into multiple units and collaborate with different artists such as Dynamic Duo, Zico, Nell and Heize for their upcoming album.^[3] On May 7, Wanna One announced the title of the new "Special" album, 1÷x=1 (Undivided) through a teaser video. It will contain the songs produced during their unit projects, which will be shown on the group's reality show Wanna One Go: X-con.^[4][5]

The title of the album is inspired by arithmetical operations like the band's previous releases: 1X1=1 (To Be One), 1-1=0 (Nothing Without You), and 0+1=1 (I Promise You).^[2] Every sub-unit track on the album is produced by a high-profile South Korean artist.^[11] The lead single, "Light" is a UK garage-inspired electropop track containing a catchy chorus and EDM breakdown. The song features all the eleven members of the band. “Forever and a Day” is an evocative pop rock track groove ballad. The song is produced by Kim Jong Wan, the vocalist of indie rock band Nell. It features the members Yoon Ji-sung, Ha Sung-woon and Hwang Min-hyun and sonically, sounds similar to the style of its writer Kim. “11” is a groovy alternative R&B track produced by Gaeko and Choiza of Dynamic Duo. The song features Lai Kuan-lin, Park Ji-hoon, and Bae Jin-young. “Sandglass” is a breezy track produced by Heize and featuring Ong Seong-wu and Lee Dae-hwi.^[11][12] The lyrics talk about with the theme of an hourglass that symbolizes memories that do not disappear, but are there for a limited time.^[13] “Kangaroo” is a summery hip hop track produced by Block B’s Zico and contains punky rhythms and melodies. The song features members Kim Jae-hwan, Kang Daniel and Park Woo-jin.^[11][12]