The Kaktovik numerals or Kaktovik Iñupiaq numerals are a base-20 system created by Alaskan Iñupiat. They are visually iconic, with shapes that indicate the number being represented.
The Iñupiaq language has a base-20 numeral system, as do all the Eskimo–Aleut languages of Alaska and Canada (and formerly Greenland). Arabic numerals, which were designed for a base-10 system, are inadequate for Iñupiaq and other Inuit languages. To remedy this problem, students in Kaktovik, Alaska, invented a base-20 numeral notation in 1994, which has spread among the Alaskan Iñupiat and has been considered for use in Canada.
The image here shows the Kaktovik digits 0 to 19. Larger numbers are composed of these digits in a positional notation: Twenty is written as a one and a zero, forty as a two and a zero, four hundred as a one and two zeros, eight hundred as a two and two zeros, and so on.