0. or 10. Dena
Dena comes from the letter Dēna (which relates to complexities of non-linear time), and symbolises both the number zero and in some ways also infinity. Ranqa was not originally base-ten, it was base-nine, which means it had no sense of zero. The numbers simply went from 1. to 9. and multiplication/addition was done in groups of nine, somewhat like how folks used to keep track of counting on an abacus. And then it was upgraded… I believe the second or third time… and a numbering system was added so that one could do maths somewhat like we do in the modern age, and one could write out in simple terms the big multi-digit numbers. Dena is used as a place holder for zero/zed/0, and to symbolise “10”.