Calculations

I tried to count the pebbles on the beach the other day
I learned that it’s much harder than it looks
You can’t use calculus, algebra or geometry
Or abacas’, fingers, toes or science books

I thought that I might group them in a hundred plots or more
Then divvy up the plots in groups of ten
And calculate the thickness of the stones upon the sand
And break those groups in smaller groups again

How many large, how many small, how many in between
So many stones each different from the rest
The boulders, they were easy, the mid size not too hard
But the gravel size would put me to the test

The seaweed and the seashells, the driftwood and the kelp
Were things I would allow for if I could
The sunlight and the shady spots, important to be sure
And the tide would play a factor, understood

I brought a solar calculator, went through all my notes
Allowed for every variable that I had
Except for one, which seemed to shift positions constantly
Just how does one account for all the crabs?