If you put the pieces in a plain jigCan't see all of the parts.Could not count the number of pieces fully.If a change is placed in a jig piece to tilt, angle 45°.Will be able to count the pieces and see the missing parts.
If you put a piece of flat jig cannot see all parts cannot count of all parts. if converted into placing parts in jig to tilt angle to 45 ° can count parts and see the missing piece. .