Mathematical Mystery Tour: September 2015

Wednesday, September 30, 2015

Blah, Blah, Blah - I just felt like sharing a litte today.

9/30/2015

Mathematics is really changing with the use of computers and the internet. WOW!

We are able to research very big numbers that were simply beyond reach 100 years ago.

For example: consider the 7,669 digit number that starts with a 1, and ends with a 3, and has 7,667 zeros between the 1 and the 3.

OK, I don't think you will see this number in the SAT or ACT tests. I probably won't help us get to Mars or cure any diseases. But this number does have a story to tell.

We could talk about how big this number is and compare it to something so we could grasp the concept - like 7,667 minutes is a bit more than 5 days. (This won't be on the SAT or ACT test either.)

But without computers we would not know that this is a prime number. The next smaller prime that starts with a 1, ends with a 3, and only has zeros between has 2,606 zeros.

This prime number is also a "Naughty" prime because is composed mostly of naughts (zeros). It is also a "Repubican" prime, because the right half of this number is a prime number, but the left half is not a prime. And, oh yeah, it's an odd number too!

I also know that the number two less than this number is not a prime, and the number two more that this number is not a prime. So this prime number is not part of a twin prime pair. With a little more work I could determine if it is part of a cousin prime pair or a sexy prime pair.

One hundred years ago if you had asked a mathematician about this number, and what properties it my or may not have he or she would only be able to tell you that it is a really big number that happens to be an odd number.

Because of computers I have know for a while that in August of next year my house will be in an area to experience a total solar eclipse. And on that day I will pause for a few minutes to observe the eclipse. And then I will return to my work of searching for an uninteresting number (which I think is impossible because I think that every number has something interesting.

Well, I better get back to my therapy.

David

Tuesday, September 29, 2015

Rumors and my NEW BLOG

9/29/2015

There is a rumor going around that mathematicians and math teachers are really pirates. They think we all want to find "x" so we will know where the buried treasure is. I am pretty sure this is not true.

HEY! I HAVE A SECOND WEBSITE THAT I JUST STARTED!

SequenceNumbers.blogspot.com

There is a number on the web that is very popular - 998,001.
Why? Because the decimal expansion of 1/998001 counts from zero to 997 without making an error.

When I first saw this I thought it was a hoax. But I did the math and it checks out - it's legit!

Then I thought to myself:"If there is one number that has this property there have got to be more!"

Well, I have found numbers that can multiply, do powers, calculate combinatorial functions, and even do the Fibonacci Sequence and other Fibonacci like sequences. I even have Sequence numbers that can count way higher than 997.

Check out the site! And be sure to start with the oldest posts which explain more about these numbers I call Sequence Numbers.

Thanks,

David

P.S. I will keep this blog going too! But I thought Sequence Numbers deserved its own blog.

(Pay no attention to the man behind the curtain.)

Monday, September 28, 2015

Brain-O Quiz Answers

9/28/2015

Answers to Last Fridays Brain-O Quiz:

1. 2. If you square it and then divide by two you end up with the same quantity. That means that squaring it and multiplying by 2 is the same operation.

2. She made $10 dollars.

3. An egg, a horse, etc.

4. Puppies

5. Only in the dictionary and the encylopedia.

Sunday, September 27, 2015

The “You Choose Your Score” Make-up Test

9/27/2015

The “You Choose Your Score” Make-up Test

If you failed the test yesterday I have decided to offer you a chance to retake the test. This is a make-up test so the numbers in the grid will be different. Please make sure you have read the direction completely and accurately. Please try not to make the same mistakes you made yesterday.

Today I am going to give you a make-up test. I’m going to give you a grid with numbers in each box. You will circle six numbers, and your test score will be the sum of the six numbers – unless the sum is more than 100, in which case you get a zero. If you went over 100 yesterday, try not to be so greedy about points. Good Luck.

Directions: Choose any number on the grid and circle it. Now cross out all of the numbers in the same row or in the same column as the number you circled. Now choose another number from the numbers that have not be crossed out or circled already – and cross out all the number in the same row or same column as the number you just circled. Repeat this step until you have circled six numbers and all of the other numbers are crossed out.

Choose wisely, Grasshopper. Be careful not to go over 100. Any score over 100 will earn you a zero.

22	23	24	19	20	21
28	29	30	25	26	27
34	35	36	31	32	33
4	5	6	1	2	3
10	11	12	7	8	9
16	17	18	13	14	15

Now add up the six numbers you circled and write it down here:

Scoring Scale:

90 to 100 = A

80 to 89 = B

70 to 79 = C

60 to 69 = D

0 to 59, or over 100 = F

David

Saturday, September 26, 2015

Another Interesting Number

9/26/2015

9,262,015 is a 441 050-gonal and a 926203-gonal number.

9,262,015 is the short leg of at least one Pythagorean triangle: 9,262,015^2 + 2,006,486,088^2 = 2,006,486,113^2.

It is a composite, congruent, deficient, Duffian, odd, odious, polite, unhappy, unprimeable and wasteful number.

It can be written as the sum of all of the positive integers from 642 to 4351.

The “You Choose Your Score” Test

9/26/2015