Three is a pink Numberjack with blue eyes. The youngest of the main Numberjacks, she rarely goes on missions due to her young age. She is often quite loud and a bit rude. She also has a collection of objects she calls "beautiful things". In later episodes, she does go out more often by herself.
In the earlier episodes, she was accompanied by bigger numbers upon going on episodes. Five usually accompanies her, though Six has also done so, once in an episode and another in an audio story. Four also has done so but things have gone wrong upon doing so. On the first time, the Launcher broke down before Four was sent out, and on a second time, Five was unable to find a 3 for Three to land on, resulting in her landing in a cave and Seven had to rescue her and escape the cave.
- Being 3 (Numbertaker).
- Data Day (Spooky Spoon).
- Fraction Action (Shape Japer).
- Getting Heavy (Spooky Spoon).
- 1, 2, 3, Go (Puzzler).
- In, Out, Shake It All About (Puzzler).
- Interesting Times (Spooky Spoon).
- Matchmaking (Numbertaker).
- Nine Lives (Puzzler).
- Seaside Adventure (Numbertaker, Problem Blob, Puzzler, Shape Japer and Spooky Spoon).
- The Container Drainer (Puzzler).
- 3 Things Good (Shape Japer).
- Wee Three Phone Home (Puzzler).
- Zero the Hero (All Numberjacks except Zero; Three got stuck by the seaside).
Three loves rushing about in the sofa. The slides and the bong pad in the Gym Room are good.
Three's beautiful things are very important, as she loves the bong ball. Her buddy blocks flew in the air with Six's buddy blocks in Nine Lives. She cannot go on some missions very often, as she's "a bit of a small number", but she loves it when she does. She will be scared when she gets launched.
Her missions can be scary when she is on her own, especially when Three sees the Puzzler. She went outside the sofa for the first time in In, Out, Shake It All About, with Five. She was trapped in the Puzzler's puzzle bubble with Five in In, Out, Shake It All About and by herself in The Container Drainer. Three loves going out on missions with Five. In Nine Lives, she went out on a mission with Six to rescue Nine from the Puzzler. She loves playing the game of Hover Dice with Four, which was seen from 7-15. In Being 3, she turned into a 4, and the Numbertaker ran home. She later insulted 4 by calling his shape ugly, as she loves playing with the youngest Numberjacks.
In 3 Things Good, she was on her own without Four during a solo mission with the Shape Japer, who hates her. In Seaside Adventure, Five found a 4 for Four to land on, but she was unable to find a 3. She landed on a 3 in a cave and she was on her own doing another solo mission, but Seven saw her.
- Three loves to annoy Four at some times.
- Three's 3d model was made using One as a base and heavily distorting the proportions.