Can we do mental arithmetic in our dreams?

[bibliophage]

I have become quite adept at mental arithmetic, so much so that I would like to be able to say that I can do it in my sleep. But I can’t. A previous thread ( can we read in our dreams? ) discussed whether we can read in our dreams. Now my question is “Can we do mental arithmetic in our dreams?”

Twice in the last few months I’ve had dreams in which I tried to, but didn’t come up with the right answer[ul][li]I tried to calculate how long it would take to fly 24,000 miles at 500 mph. The answer I came up with was 480 hours. I had no inkling the answer was wrong until I woke up, and immediately realized it wasn’t right.[/li]I was a cashier in a grocery store. A woman bought $245.11 in groceries and tried to pay with a $1,000 bill. I stood there for what seemed like ten minutes trying to figure out how much change to give her. Every time I tried to do it, I came up with a different answer (and never the right one).[/ul]So is it possible to do it, or not? Keep in mind that I’d have no trouble at all with problems like these (and much worse) while awake.

[lee]

I can at least. I remember having nightmares about division of polynomials. I also did calculus homework in quite a few pleasant dreams.

[Steve-o]

I’ve read and done some very basic math in my dreams. Mostly addition of 1 or 2 digit numbers.

It appears as if you came close with your 480 hours. You got the right numbers, just the wrong magnitude.

[Chronos]

I had a dream just recently where I did mental arithmatic. I don’t remember now what it was, but I remember double-checking it when I woke up, and it was correct. Unless, of course, I dreamt the part about double-checking it, too, but I don’t think so… Am I awake right now?

[Cabbage]

This is from The Mathematician’s Mind: The Psychology of Invention in the Mathematical Field by Jacques Hadamard:

Only one remarkable observation (of “mathematical dreams”) is reported by the prominent American mathematician, Leonard Eugene Dickson, who can positively assert its accuracy. His mother and her sister, who, at school, were rivals in geometry, had spent a long and futile evening over a certain problem. During the night, his mother dreamed of it and began developing the solution in a loud and clear voice; her sister, hearing that, arose and took notes. On the following morning in class, she happened to have the right solution which Dickson’s mother failed to know.

Not specifically arithmetic, but a very interesting story nonetheless.

[Becky]

As if it weren’t enough to do hours of math homework nearly every day (I’m a math major), I’ve also done homework in my sleep. Wow … what a life!

[Bear_Nenno]

What a coincidence!! Last night in my dream, I gave a sandwich or something to my girlfriend. She asked how much I paid for it. I told her 4.50. Then she wrote me a check for 99.50. I saw that it was 95 dollars over and asked her if it was for the money she owed me. She said yes. I said cool.

Well there you have it. It can be done, I did it last night. I know it was only subtraction, but I don’t think I could do all that long division and polynomial stuff in my head while awake. Not without a calculator. So I definitely couldn’t do it while sleeping.