Quipu were constructed out of a large main cords with smaller "pendant cords" attached. Pendant cords would have knots that meant various things. Pendant cords showing numeric data would have a number between 1 and 9, with an empty space meaning 0, with the position of the numbers distance to the top signifying its numerical place, eg. ones, tens, hundreds. Pendants with "words" are formed by syllable-like knots place close to another to form a "word". Calendrical quipu had multiple weeks per pendant, with knots to specify special dates like Sundays, birthdays, and death dates.

Quipu were helpful when it came to the collection of tribute payments, as a quipu accompanying the tribute acted somewhat like a receipt, telling the tribute collector which items were given and how many there were. Additionally, quipu worked well for census collection, with a similar receipt format being presented to the Inca government to tell them the state of their peoples. Quipu is still used infrequently in rural Peru, mostly by shepherds to keep track of their goat and sheep populations.