- 14 Jan '05 05:37

It's a pretty straightforward calculation. If you think of multiplying by hand, you'll end up adding stacks of ones. Each stack will have progressively more ones until the center, which has 9 (the number of ones in your two original numbers) and so you'll see that pattern.*Originally posted by UncleAdam***did you know that**

111111111 X 111111111 = 12345678987654320

i thought i was kinda interesting.

PS i not sure if it belongs here but it didnt seem like it should go in the general fourm so i put it here - 14 Jan '05 15:01

You've made a typo, probably, as it should be 12345678987654321.*Originally posted by UncleAdam***did you know that**

111111111 X 111111111 = 12345678987654320

i thought i was kinda interesting.

PS i not sure if it belongs here but it didnt seem like it should go in the general fourm so i put it here - 14 Jan '05 21:49 / 1 edit

Then your calculator's defective. You need prime factors of 5 and 2 for a non-trivial number to end in 0, and 111,111,111 does not have either factor. The correct product is indeed 12345678987654321*Originally posted by UncleAdam***nope, thats the way it came out on the calculator.** - 15 Jan '05 02:52

I wouldn't rush to call the calculator defective, but it certainly may not be precise enough to display such a large number correctly.*Originally posted by UncleAdam***nope, thats the way it came out on the calculator.**

My Microsoft Excel gives 12345678987654300 as the answer. The last two digits are suspect when the question was 111111111 * 111111111.

The ancient art of handwritten math (!) would quickly show you that your calculator is not telling the full story:

111111111

x 111111111

-------------

111111111

1111111110 ... STOP

Every line after this will have at least one placeholder zero, so the least significant digit will remain 1! - 18 Jan '05 00:54

I agree with you, but apparently Bill Gates disagrees, as Excel does give the answer of: 12345678987654300. I was tuaght in school that any number ending 1 times any number ending in 1 gave a product ending in 1. But Bill Gates must be right - he couldn't possibly have gotten so stinking rich by being wrong... ..could he?*Originally posted by TheMaster37****cough* something ending in a 1 multiplied with something ending in a 1 ends in a 1. It's as simple as that**