## Re: [Mental Calculation] calendar calculation

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• Ha Jan, That s very very nice: indepently of eachother and generating the same suggestion!! How is it possible. And your logic argument is very strong: indeed
Message 1 of 14 , Mar 1, 2010
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Ha Jan,

That's very very nice: indepently of eachother and generating the same suggestion!! How is it possible.

And your logic argument is very strong: indeed where is the logic when typing 1 = correct and writing 1 is wrong.

Best regards Jan.

Willem

----- Oorspronkelijk bericht -----
Van: Jan van Koningsveld
Aan: MentalCalculation@yahoogroups.com
Verzonden: zondag 28 februari 2010 21:19
Onderwerp: Re: [Mental Calculation] calendar calculation

Dear Willem,

You suggested :

>The calculator has to write on his paper how he works:
>1 = sunday, 2 = monday etc
>1 = monday, 2 = tuesday etc.
>1= saturday, 2 = sunday etc.

>and then behind the question mention the number he has calculated.

This is what I suggested as well. Why is it allowed to type numbers when using a computer program, but when writing it on paper we have to use letters ? No logic here. Or is it ?

Kind regards
Jan

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]
• Dear Jan, The logic comes from the history of this category. In the first record attempts the answer had to be given orally, and one more step was necessary to
Message 2 of 14 , Mar 1, 2010
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Dear Jan,

The logic comes from the history of this category. In the first record attempts the answer had to be given orally, and one more step was necessary to come from a number to a day of the week.

I have to agree that today (at the time of computer contests) this rule could be adapted. I do not really have a problem with using numbers, because this would not give an advantage or disadvantage to anyone.

However, in fact I would prefer to provide the seven options as boxes to check behind each question. The calculators would have to mark the correct box which is maybe even faster than writing down a number. (And it will make the correction much easier for us.) Those who want to keep the old system to write down the days should still have the option to do so.

Other than in the ongoing discussion about the types of questions and the scoring system, I hope it should be possible to come to an agreement about such rather small details without too much problems.

Ralf

--- In MentalCalculation@yahoogroups.com, "Jan van Koningsveld"
> >The calculator has to write on his paper how he works:
> >1 = sunday, 2 = monday etc
> >1 = monday, 2 = tuesday etc.
> >1= saturday, 2 = sunday etc.
>
> >and then behind the question mention the number he has calculated.
>
> This is what I suggested as well. Why is it allowed to type numbers when using a computer program, but when writing it on paper we have to use letters ? No logic here. Or is it ?
• ... Dear Willem, Wim Klein was right: For most of us calculating the day of a week is as easy as going forward for a distance of 100 m. But this does not mean
Message 3 of 14 , Mar 3, 2010
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--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...> wrote:

> I remember as the day of yesterday that Wim Klein said to me "Calendar calculation is so simple, you are too good for it".

Dear Willem,

Wim Klein was right: For most of us calculating the day of a week is as easy as going forward for a distance of 100 m.
But this does not mean that it is not a challenge to solve 100 such tasks in one minute or to run the 100 m in less than 10 seconds which is very far from being easy, and I think both contests are interesting.

Ralf
• Dear fellow calculators, In a small Dutch magazine an antropologist published a kind of table in which in October 2010 are mentioned 5 Fridays, 5 Saturdays and
Message 4 of 14 , Nov 2, 2010
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Dear fellow calculators,

In a small Dutch magazine an antropologist published a kind of table in which in October 2010 are mentioned 5 Fridays, 5 Saturdays and 5 Sundays.

He says that this happens once in 823 years. Certainly he does not know that every 28 years the calendars are equal.

My conclusion; the best he can do is stay an antropologist, and not participate in any tournament.
Unfortunately he published aninomously.

Regards,

Willem Bouman

[Non-text portions of this message have been removed]
• Dear Willem Nice insights, #28 is indeed the number of a calendar s re-occurance. (7 different days for the leap day that happens every 4 years) Though, in
Message 5 of 14 , Nov 8, 2010
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Dear Willem

Nice insights, #28 is indeed the number of a calendar's re-occurance.
(7 different days for the leap day that happens every 4 years)

Though, in October's case there is no leap month concerned, so the case 'October 3rd = Sunday' calendars (to get 5 Fridays, 5 Saturdays ,5 Sundays) as it happens in 2010, can also happen exactly 14 times in this century. And, it has to do with years ending in 04,10,21,27,32, 38,49,55,60,66, 77,83,88,94.

Regards,
Nodas

--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...> wrote:
>
> Dear fellow calculators,
>
> In a small Dutch magazine an antropologist published a kind of table in which in October 2010 are mentioned 5 Fridays, 5 Saturdays and 5 Sundays.
>
> He says that this happens once in 823 years. Certainly he does not know that every 28 years the calendars are equal.
>
> My conclusion; the best he can do is stay an antropologist, and not participate in any tournament.
> Unfortunately he published aninomously.
>
> Regards,
>
> Willem Bouman
>
> [Non-text portions of this message have been removed]
>
• Good afternoon Nodas, Aha, this is better! The sequence you mention is the famous 6, 5, 6,11 sequence, or in this case 6, 11, 6, 5. It was Robert Fountain who
Message 6 of 14 , Nov 9, 2010
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Good afternoon Nodas,

Aha, this is better!
The sequence you mention is the famous 6, 5, 6,11 sequence, or in this case 6, 11, 6, 5. It was Robert Fountain who explained this to me.

Regards,

Willem

----- Oorspronkelijk bericht -----
Van: Nodas Boukovalas
Aan: MentalCalculation@yahoogroups.com
Verzonden: dinsdag 9 november 2010 3:26
Onderwerp: [Mental Calculation] Re: calendar calculation

Dear Willem

Nice insights, #28 is indeed the number of a calendar's re-occurance.
(7 different days for the leap day that happens every 4 years)

Though, in October's case there is no leap month concerned, so the case 'October 3rd = Sunday' calendars (to get 5 Fridays, 5 Saturdays ,5 Sundays) as it happens in 2010, can also happen exactly 14 times in this century. And, it has to do with years ending in 04,10,21,27,32, 38,49,55,60,66, 77,83,88,94.

Regards,
Nodas

--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...> wrote:
>
> Dear fellow calculators,
>
> In a small Dutch magazine an antropologist published a kind of table in which in October 2010 are mentioned 5 Fridays, 5 Saturdays and 5 Sundays.
>
> He says that this happens once in 823 years. Certainly he does not know that every 28 years the calendars are equal.
>
> My conclusion; the best he can do is stay an antropologist, and not participate in any tournament.
> Unfortunately he published aninomously.
>
> Regards,
>
> Willem Bouman
>
> [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]
• Good evening Willem, Well mentioned. Plus, any 4 consecutive numbers of this sequence 11,6,5,6,11,6,5,6,11,6.., adds up to 28 which is the re-occurance
Message 7 of 14 , Nov 10, 2010
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Good evening Willem,

Well mentioned. Plus, any 4 consecutive numbers of this sequence 11,6,5,6,11,6,5,6,11,6.., adds up to 28 which is the re-occurance number.(something like the frequency in Sinusoidal waves in physics)

Even the '11' gap can theoritically be split to 5.5.
I.e. between 2010 and 2021, the case '2015.5 October 3rd=Sunday' means that '2015 October 3rd=Saturday' and '2016-Oct-03=Monday' respectively.
So 2015.5, 2043.5 and 2071.5 can be embedded to the 14 number pattern in my previous message, if someone finds it helpful.

Best wishes
Nodas

--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...> wrote:
>
> Good afternoon Nodas,
>
> Aha, this is better!
> The sequence you mention is the famous 6, 5, 6,11 sequence, or in this case 6, 11, 6, 5. It was Robert Fountain who explained this to me.
>
> Regards,
>
> Willem
>
>
>
> ----- Oorspronkelijk bericht -----
> Van: Nodas Boukovalas
> Aan: MentalCalculation@yahoogroups.com
> Verzonden: dinsdag 9 november 2010 3:26
> Onderwerp: [Mental Calculation] Re: calendar calculation
>
>
>
> Dear Willem
>
> Nice insights, #28 is indeed the number of a calendar's re-occurance.
> (7 different days for the leap day that happens every 4 years)
>
> Though, in October's case there is no leap month concerned, so the case 'October 3rd = Sunday' calendars (to get 5 Fridays, 5 Saturdays ,5 Sundays) as it happens in 2010, can also happen exactly 14 times in this century. And, it has to do with years ending in 04,10,21,27,32, 38,49,55,60,66, 77,83,88,94.
>
> Regards,
> Nodas
>
>
> --- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@> wrote:
> >
> > Dear fellow calculators,
> >
> > In a small Dutch magazine an antropologist published a kind of table in which in October 2010 are mentioned 5 Fridays, 5 Saturdays and 5 Sundays.
> >
> > He says that this happens once in 823 years. Certainly he does not know that every 28 years the calendars are equal.
> >
> > My conclusion; the best he can do is stay an antropologist, and not participate in any tournament.
> > Unfortunately he published aninomously.
> >
> > Regards,
> >
> > Willem Bouman
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
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