It came as a bit of a shock to my friend living in Poland that a box of eggs is not really a dozen. Why is that?
Some claim that eggs were sold in England in twelves so that each could cost a penny and the whole box would make for a shilling (12 pennies). That This might be true, but the system of counting in twelves can be traced back to as early as ancient Mesopotamia and it was also present in Poland. Phraseology, which is a great vehicle and preservative for culture, still retains phrases like “tuzin jaj” (a dozen eggs) or “kopa jaj” (five dozen eggs), yet now they are sold in packs holding 6, 10 or 30 pieces.
It might have changed during the time of partitions, which coincided with adoption of the metric system throughout Europe. In Russia, as well as in Germany and Austria, eggs are sold in packs of 10, so it might have been one of the numerous ways these countries influenced our culture. One way or another, be sure you stock up as Easter is just around the corner, and if you are going to spend it in Poland, you may need to get a box more.