There are total six layers, each layer separated by cardboard. first to fifth layers each layer contains 500 pcs, Sixth layer is 490pcs.
Each layer has 4 corners. Each corner is 120pcs,12 bundles each of which is 10pcs.
No13 in picture 1(attached) is 20pcs, so the quantity for one lay is 120X4+20=500
For six layer, the No13 is 10pcs, so the sixth layer is 120X4+10=490pcs
