Check your mental calculating speed: quickly add up the numbers listed below.
What do you get as a total?
| 500 520 1000 30 40 1000 + 10 –––-– |
Calculate Quickly
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Rudi
- gamma jay
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- Location: Cape Town
Calculate Quickly
Check your mental calculating speed: quickly add up the numbers listed below.
What do you get as a total?
Regards,
Rudi
If your absence does not affect them, your presence didn't matter.
Rudi
If your absence does not affect them, your presence didn't matter.
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HansV
- Administrator
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- Joined: 16 Jan 2010, 00:14
- Status: Microsoft MVP
- Location: Wageningen, The Netherlands
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Rudi
- gamma jay
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- Location: Cape Town
Re: Calculate Quickly
Correct... 
Spoiler
Yep, the last 10 is where things go awry!
Everyone will get to 3090; but while calculating fast, the mind will add 10 to 3990 (for some strange reason) and the result is 4000.
I think it is to do with the mind being conditioned to formulate to a rounded number.
Alternatively, when the 90 + 10 becomes 100, one adds the 1 (of the 100) to the 3 (of the 3000) and gets to 4000.
Everyone will get to 3090; but while calculating fast, the mind will add 10 to 3990 (for some strange reason) and the result is 4000.
I think it is to do with the mind being conditioned to formulate to a rounded number.
Alternatively, when the 90 + 10 becomes 100, one adds the 1 (of the 100) to the 3 (of the 3000) and gets to 4000.
Last edited by Rudi on 08 Dec 2015, 12:39, edited 1 time in total.
Regards,
Rudi
If your absence does not affect them, your presence didn't matter.
Rudi
If your absence does not affect them, your presence didn't matter.
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TonyE
- 3StarLounger
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- Location: Buckinghamshire, England
Re: Calculate Quickly
Spoiler
22
There are three 1s, two 5s, one each of 2,3 and 4 plus twelve 0s
There are three 1s, two 5s, one each of 2,3 and 4 plus twelve 0s
Tony
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Rudi
- gamma jay
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- Location: Cape Town
Re: Calculate Quickly
Yeow Tony!
That is abstract to say the least!
Major out of the box thinking there!
That is abstract to say the least!
Major out of the box thinking there!
Regards,
Rudi
If your absence does not affect them, your presence didn't matter.
Rudi
If your absence does not affect them, your presence didn't matter.
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BobH
- UraniumLounger
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Re: Calculate Quickly
You got me, RudY!
Bob's yer Uncle
Dell Intel Core i5 Laptop, 3570K,1.60 GHz, 8 GB RAM, Windows 11 64-bit, LibreOffice,and other bits and bobs
| (1/2)(1+√5) |
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Rudi
- gamma jay
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- Location: Cape Town
Re: Calculate Quickly
I think the lounge has a vYrus! 
Regards,
Rudi
If your absence does not affect them, your presence didn't matter.
Rudi
If your absence does not affect them, your presence didn't matter.
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HansV
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AlanMiller
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Re: Calculate Quickly
It's probably just me, but when I saw the "quickly" in the instruction, I probably adopted a method which would actually avoid the common error. I swept up all the small numbers (30+40+10=80) and tacked it onto the convenient 520 (520+80=600) then just tallied the hundreds (600+500=1100) and added it to the thousands (1100+1000+1000=3100). Sorry I got it wrong ... or right. 
Alan
Alan
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Rudi
- gamma jay
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Re: Calculate Quickly
Clever route to follow...
I would have done it so...
20+30+40+10=100 (Slurp up all the 10's)
500+500=1000 (Then the 100's)
1000+1000=2000 (Then the 1000's)
2000+1000+100
Y you ask... well, Y not!
I would have done it so...
20+30+40+10=100 (Slurp up all the 10's)
500+500=1000 (Then the 100's)
1000+1000=2000 (Then the 1000's)
2000+1000+100
Y you ask... well, Y not!
Regards,
Rudi
If your absence does not affect them, your presence didn't matter.
Rudi
If your absence does not affect them, your presence didn't matter.