Jaya Ma! Congratulations to all of the end of Navratri!
I care about one question. When doing purashcharana, what do you need for counting a certain number of mantras, even if in the mala, we have 108 beads, no 100? And also, if I do daily for example 5000 jap, does that mean I have to repeat 50 malas? Then how do I count the number of malas and number and what to do with the eight beads in every hundred?
In ISCKON, there available a Mala called Sakshi Mala that has about 15 to 20 beads in it which you hold and count in your left hand, when you do Japa in the right hand with regular 108 Rosary and once you finish one round, you can count one Bead in the left hand Sakshi Mala (You can call it by any name of your choice).
You can conveniently prepare or modify already existing mala for this purpose.
There is a simple way of approach for this issue. You have have small paper and pen near you while doing japam. Once 100 / 108 is over, make one line. same way you can make lines for every 100. Or, you can keep some flowers near you and for each 100, you can take a flower apart and keep it separately.