It is used for telling the juzu while reciting Buddhist invocation, and it is possible to recite 32,400 times (27 times 20 times 6 times10 makes 32,400) by telling the juzu with all beads other than Fukudama.
念仏を唱える時繰り、副珠以外のすべての珠を使って繰ると27×20×6×10＝32,400遍唱えられる。