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137/2
ABCD
--+-
137
7
+35
3
+15
1
+05
--+-
0685
68.5
137/4
ABCDE
--+--
137
7
+175
3
+075
1
+025
--+--
03425
34.25
137/8
ABCDEF
--+---
137
7
+0875
3
+0375
1
+0125
--+---
017125
17.125
137/16
ABCDEF
--+---
137
7
+4375
3
+1875
1
+0625
-+----
085625
8.5625
137/32
ABCDEFG
--+----
137
7
+21875
3
+09375
1
+03125
-+-----
0428125
4.28125
137/64
ABCDEFGH
--+-----
137
7
Borrar 7 en C
+109375
3
Borrar 3 en B
+046875
1
Borrar 1 en A
+015625
-+------
02140625
2.140625
"+" indica la posición de la columna unidad antes y después de la operación.
1-digit addition: type
1-digit subtraction: type
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
+1
1
1
1
1
2
1
1
1
1
3
-1
3
1
1
1
1
2
1
1
1
1
+2
1
1
1
2
2
1
1
1
3
3
-2
3
3
1
1
1
2
2
1
1
1
+3
1
1
2
2
2
1
1
3
3
3
-3
3
3
3
1
1
2
2
2
1
1
+4
1
2
2
2
2
1
3
3
3
3
-4
3
3
3
3
1
2
2
2
2
1
+5
1
1
1
1
1
3
3
3
3
3
-5
3
3
3
3
3
1
1
1
1
1
+6
1
1
1
1
3
3
3
3
3
3
-6
3
3
3
3
3
3
1
1
1
1
+7
1
1
1
3
3
3
3
3
3
3
-7
3
3
3
3
3
3
3
1
1
1
+8
1
1
3
3
3
3
3
3
3
3
-8
3
3
3
3
3
3
3
3
1
1
+9
1
3
3
3
3
3
3
3
3
3
-9
3
3
3
3
3
3
3
3
3
1
0
1
2
3
4
5
6
7
8
9
+1
1
1
1
1
2
1
1
1
1
3
+2
1
1
1
2
2
1
1
1
3
3
+3
1
1
2
2
2
1
1
3
3
3
+4
1
2
2
2
2
1
3
3
3
3
+5
1
1
1
1
1
3
3
3
3
3
+6
1
1
1
1
3
3
3
3
3
3
+7
1
1
1
3
3
3
3
3
3
3
+8
1
1
3
3
3
3
3
3
3
3
+9
1
3
3
3
3
3
3
3
3
3
0
1
2
3
4
5
6
7
8
9
-1
3
1
1
1
1
2
1
1
1
1
-2
3
3
1
1
1
2
2
1
1
1
-3
3
3
3
1
1
2
2
2
1
1
-4
3
3
3
3
1
2
2
2
2
1
-5
3
3
3
3
3
1
1
1
1
1
-6
3
3
3
3
3
3
1
1
1
1
-7
3
3
3
3
3
3
3
1
1
1
-8
3
3
3
3
3
3
3
3
1
1
-9
3
3
3
3
3
3
3
3
3
1
q1
d1
10000
1109889
20000
739889
30000
369889
40000
-111
50000
-370111
60000
-740111
70000
-1110111
80000
-1480111
90000
-1850111
Proto-Cuneiform tablet: administrative account of barley distribution with cylinder seal impression of a male figure, hunting dogs, and boars. Probably from the city of Uruk. Jemdet-Nasr period circa 3100 –2900 BCE
The "SANGA" character is believed to be a pictorial representation of a Sumerian abacus.
Woods, Christopher (2017), "The Abacus in Mesopotamia: Considerations from a Comparative Perspective", The First Ninety Years: A Sumerian Celebration in Honor of Miguel Civil , De Gruiter, ISBN 9781501511738 ; ; ; ; ;
Write caption here!
A
B
C
D
E
F
G
H
I
T
T
T
T
T
T
T
T
1
Write caption here!
A
B
C
D
E
F
G
H
I
K
J
L
M
9
18
9
0
0
1
0
0
0
0
9
9
9
5+2 abacus number representation
A
B
C
D
E
F
G
H
I
J
K
L
0
1
2
3
4
5
5
6
7
8
9
10
5+2 abacus number representation (cont.)
A
B
C
D
E
F
G
H
I
J
K
L
10
11
12
13
14
15
15
16
17
18
19
20
Starting division 998001÷999
A
B
C
D
E
F
G
H
I
J
K
L
M
9
9
8
0
0
1
9
9
9
Just after applying division rule 9/9>9+9
A
B
C
D
E
F
G
H
I
J
K
L
M
9
18b
8
0
0
1
9
9
9
A
A
A + 1 =
4
5
text
Write caption here!
A
B
A
B
B +5 =
4
6
F
1
text
Write caption here!
A
B
A
B
B + 5 =
9
6
T
1
text
First 3 digits of
456.7890123
{\displaystyle {\sqrt {456.7890123}}}
preparing the dividend
Abacus
Comment
ABCDEFGHIJKL
4567890123
Enter x aligning digit pairs from AB, CD, etc.
-4
Subtracting 2^2 from first group
567890123
2839450615
Halving remainder and rest of digits pairsa
2 2839450615
Entering first root digit in A
21
Dividing BCD by A
-2
-05
Subtracting B^2/2=0.5 from CDE
21 789450615
213789450615
Dividing CDEF by AB
-6
-3
-45
Subtracting C^2/2=4.5 from CEFG
213154950615
etc.
^a as explained in Chapter: [[../../Division/Division by powers of two/|Division by powers of two]].
First 3 digits of
456.7890123
{\displaystyle {\sqrt {456.7890123}}}
preparing the dividend
Abacus
Comment
ABCDEFGHIJKL
4567890123
Enter x aligning digit pairs from AB, CD, etc.
-4
Subtracting 2^2 from first group
567890123
2839450615
Halving remainder and rest of digits pairsa
2 2839450615
Entering first root digit in A
21
Dividing BCD by A
-2
-05
Subtracting B^2/2=0.5 from CDE
21 789450615
213789450615
Dividing CDEF by AB
-6
-3
-45
Subtracting C^2/2=4.5 from CEFG
213154950615
etc.
User Jccsvq (discuss •contribs ) has contributed the base or initial text of this book by adapting some of his writings from his personal website jccAbacus .
Article texta more textb more text c .
Bulleted textb
Bulleted textc .
(intervening text...)
^a Text for note a.
^b Text for note b.
^c Text for note c (with extended highlighting).