One is main scale and another is called Vernier scale; now on Vernier scale you can see 0 and I think it is written 9 and then bigger one no 0 and there is 1 means in between there are 10 divisions ok.
একটি হল মেইন স্কেল অন্যটিকে ভার্নিয়ার স্কেল বলে।