I really can’t swear just what happens out there,
  When people go shopping at random,
But arithmetic rules that we all learn in school
  Are the first thing we choose to abandon.

Yes, some are aware E=mc²
  Or memorize log’rithm tables,
But that sort of lore does not work at the store,
  And not knowing it doesn’t disable.

Some shoppers compare the size of two wares
  Or rely on their blind intuition,
Some choose what’s on sale but never avail
  Themselves of their long-hand division.

Now Kuhn and Capon made a study thereon
  Concluding most shoppers are backwards,
But our good name is saved, for the worthy Jean Lave
  Will show that there are other factors.

It may be we’ve spilled our last carton of milk
  And rush to the store to restock it,
But once we are there we are sharply aware
  That we’ve only a buck in our pocket.

In such an event we are very content
  To shell out a bit more per unit,
When the total amount is what really counts;
  Then we take home our milk and consume it.

We may have no space or know it will waste,
  And therefore we purchase the smaller.
There’s more to be weighed than the price we have paid,
  Or the ounces of milk for the dollar.

I need not go on, for my point it is won,
  Examples of this there are myriad;
But whatever the case, it should be no disgrace,
  And our actions are nothing to sneer at.

Now Capon and Kuhn may have spoken too soon,
  Their results are both tragic and shocking,
But the question remains: have they ever, the twain,
  Attempted to do their own shopping?