Incalculable Symbol

Question

My nephew recently received this as a piece of homework (he is seven):

"How many grains of sand are there in the world?"

Obviously he Googled the question and it came back with "It is incalculable". Knowing that I'm `into' maths, he asked me if there is a symbol to mean incalculable'. I am not aware of one (I do Pure maths, so it doesn't come up very often). I told him that I do't know, but that I will ask the lovely people of Stackexchange to help me.

Does anyone have any idea if there does exist such a symbol?

Answer 1

If you count them, i am sure you will forget at least one grain. the number of grains is a function of time $$N (t) $$ which depends on many parameters and whose evolution equation is very complicated.

Your question has not to be asked. i have been downvoted cause i answerd a bad philosophic question.

Answer 2

There is no symbol that means incalculable. Probably the closest you'll get is $\text{DNE}$ for "does not exist" and that's not applicable here.

Is "it's incalculable" really all that was found in the google search? I just googled How many grains of sand are there in the world? and got results much more interesting than that.

I think it's clear (although perhaps not to a 7-year-old, and understandably so) that an exact answer is not expected. Rather, the point of this seems to be an exercise in estimating very large quantities. Some of the results in my search talked about comparing the number of grains of sand to the number of stars in the universe. An interesting read but may not be a good starting point. I suggest also googling stuff about how to estimate large quantities, and perhaps, more specifically, how to estimate the number of grains of sand in the world. The key word here being estimate.

Answer 3

"Incalculable" is not a symbol. It is an adjective, which means "cannot be calculated" and, as such, a false response to the question. (Probably a prank or a software place holder from Google programmers.)

Back to your nephew's homework, the teacher probably wanted an order-of-magnitude estimate. Something like,

(total area on Earch covered by sand) * (average thickness of the sand) / (average volume of a sand grain).