To Go Meaning

(idiomatic) Remaining. To finish. (In a group of events or items) belonging to the subgroup that have not passed or have not been finished or have not been addressed yet.

Example:   I'd like two burgers, two small orders of fries and two shakes, to go.
  In my country, we go to public school for 12 years, and I have three more years to go.
  Right now, out of four bicycles, that's two down and two to go.