Learn about the Quipu!
What a Quipu is
Quipu is a number system based on knots on a string.It was used as a calculator.There is one main string which all of the other strings hang from.those strings have a series of knots on them. The type of knot represents a certain number.The placement of the string on the main string has a meaning too.It meant that they were units of 1.10,100,and so on.
What a quipu looks like:
Where the quipu came from
The quipu came from Andean South America.it was historically used by the Incas.It is unknown whether or not the Incas invented the quipu,but we do know that they still use the quipu. The Incas use a decimal number system like we do.In base-10,the number 5436 means (5x1000)+(4x100)+(3x10)+(6x1).That is called expanded form or expanded notation.