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        ****** Congratulations to all who entered! *******
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               ~ Winners/Solvers of puzzle #405 ~
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Barry Spence
Red Deer,  AB  - CANADA

Mrs. Spence's 3/4 Class
Joseph Welsh School - Red Deer, AB - Canada

Aaron D and James R
SOMS - Blauvelt, USA

The answer I found is
18, 11, 15, 14, 19, 17, 16, _10_, _13_, _12_, _20_
and this is how I found it:
I wrote the numbers in letters like this:
eighteen
eleven
fifteen
fourteen
nineteen
seventeen
sixteen
and I saw that they are in alphabetical order and that the missing 
numbers fit in alphabetical order after that:
ten
thirteen
twelve
twenty.
Francisco A. Cicero, 9 years old, bilingual 4th grade,
San Elizario Elementary School - El Paso, Texas, USA

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Jonathan Pasco - Grade 5
Pine Grove Public School/Ecole Pine Grove - Oakville, Ontario Canada 

18, 11, 15, 14, 19, 17, 16, 20, 20, 23, 17

to go from 18 to 15 subtract 3
to go from15 to 19 add 4 
to go from 19 to 16 subtract 3
to go from 16 to 20 add 4
( the pattern is subtract 3 plus 4 for every other number)

to go from 11 to 14 add 3
to go from 14 to 17 add 3
to go from 17 to 20 add 3

(the pattern is add 3 for the other numbers)

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Spenser Smith from Oakville Canada.
This is my answer to #405.  10, 12, 13, 20
I added up the digits in each number.  Then I looked for the difference
between each number in order.  The sum of the digits plus or minus the
difference between each number gave me the next number.  For example I
added one plus 6 in 16 to get 7.  Then I took 6 away to get one plus zero
in the TEN.  This is hard to explain!

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        ****** Congratulations to all who entered! *******
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