Three Hundred, or 300 is a Numberblock made up of 300 blocks. Her first and only appearance was in One Thousand and One. She is voiced by Beth Chalmers.
Appearance[]
In One, Ten and One Hundred's imagination, she looks like a big Three, despite the lack of any juggling balls.
300 is a triangular number (1-24 added together). Despite this, she doesn't have a Step Squad mask. This is probably because the creators didn't check if 300 was a step squad, or that the trait is from her "base version", Three, who doesn't have a permanent step mask, but is seen wearing one occasionally.
It is possible that since 300 never had a physical appearance, her design may differ physically (Sixty-Four's design is different than her drawing in More to Explore, having eyebrows).
300 is the biggest numberblock to be a Step Squad.