Prayer ropes/beads in Greek are called "kombioskini", while in Slavic countries they are called "chotki". Tradition says that monks used to gather and move small pebbles to count their prayers.
Prayer ropes come in different bead or knot numbers. Many of the numbers are associated with an event in the church, for example, 33 for the years of Christ's life. Fifty is associated with the number of days between Pascha and Pentecost. One Hundred days from the beginning of the Great Fast until Pentecost. Sometimes the knots are referred to as "Tears of the Mother of God