Some relevant tools for Implementation of level-index arithmetic for very large numbers were proto-typed by Swastik Banerjee (formerly at Wolfram Research).

Try working through Mathematica fast intro for math students

Then look at some of the other introductory material available on the web.

Or if you are very very old school then there are many good books printed on paper to help you.

For the specific errors that you saw when you tried to type in the example that I showed you, you cannot insert spaces in the middle of things, Mathematica is INTENSELY case sensitive so you cannot use lower case letters when I showed upper case letters, you cannot substitute ( for [ or ) for ] because those mean completely different things to Mathematica.

Perhaps, if you can, scrape my example off the screen and paste that into the Mathematica screen and see if that works.

syntax error: Log10 [96717311574016] * can't be followed by [16777216^7 * 8^2].

Deleted. My post was a mistake. By routine habit I considered exponentiation. While Swastik's idea involves tetration.

its like it has an end but NO BEGINNING! I don't remember how to use logarithms. Do they give me info about the first digits, lets say a million?

23 minutes ago I posted showing how you could probably get some correct leading digits.

Changing the subject. If you type something in and it doesn't work then posting that you typed something in and it didn't work does not give anyone the information they need to be able to help you. That is because your screen is turned just a bit and everyone here can't quite read your screen to see what you did.

And Mathematica keeps a hidden cache of values you have previously assigned to variables. If you don't know this then you can often get things you don't expect because you didn't realize what you had already assigned to variables. You can try restarting Mathematica and that will usually clear the cache.

If that doesn't work then scraping off your screen and pasting that into a message asking for help will usually help. But you need to carefully look at that and make certain that the posting process didn't mangle and change what you pasted into your message.

It seems to me that you should try contacting Wolfram customer support and see if they can help you get this fixed.

I know how to calculate the rightmost digits. The problem is I can't figure out how to calculate the leftmost (first) digits of my expression ((96717311574016^16777216^4)^8^4)^7)^2 * 7^11 and ANY number in GENERAL, I can't calculate the first ten thousand digits myself. Also clicking five minutes.nb in my notes doesn't actually open it.

I now have it on my computer but I am still clueless how to use the language.

thanks so much bill! so now my question is how to I calculate the last MILLION digits of my expression (((96717311574016^16777216^4)^8^4)^7)^2 * 7^11? I am basically asking to calculate mod 10^1, 000, 000 of 96717311574016^(16777216^4 * 8^4 * 7 * 2) * 7^11. but first I need to know how to use Mathematica on my computer.