Proper radicand setting on the Soroban
Always place the radicand on the Soroban in such a way that its unit digit fall on as unit rod.
Proper roots setting on the Soroban (New)
I - Radicand consists
of whole numbers only (one of the 2 following rules must
be observed on
placing the 1st. root digit
Ia. When the last group is found complete, set the root 1st figure
immediately on the first order
to the left the radicand
Ex. Ia:
______ √362404 = 602 G F E D C B A ► unit rod
… 3 6 2 4 0 4
6 0 2
↑
1st root digit
|
Ib. When the last group is incomplete (one digit only), set the root first figure on the 2nd column to the left of the radicand.
Ex. Ib:
_______
√ … 256 = 16
E D C B A ► unit rod
… 2 5 6
1 6
↑
1st root digit
|
II. As the ZEROS are never taken into account while setting the root digits on the Soroban, nevertheless one should remember that the first figures correspond to the first root digits of a decimal root. So, the same criteria must be observed, while extracting the square root of a pure decimal or mixed number.
Ex. IIa:
_______
√0.2025 = 0.45
A B C D E
0. 2 0 2 5
4 5
↑
1st digit = 1st root digit
|
Ex. IIb:
_______
√0.0196 = 0.14
A B C D E
0. 0 1 9 6
1 4
↑
1st digit = 1st root digit
|
Ex. IIc:
_________
√0.002025 = 0.045
A B C D E F G
0. 0 0 2 0 2 5
4 5
↑
1st digit (zero) ≠ 1st root (4) digit
|
Ex. IId:
___________
√0.00015129 = 0.0123
A B C D E F G H I
0. 0 0 0 1 5 1 2 9
1 2 3
↑
1st digit (zero) ≠ 1st root (1) digit
|
Ex. IIe:
_________ √0.000025 = 0.005 A B C D E F G
0. 0 0 0 0 2 5
5
↑
1st digit (zero) ≠ 1st root (5) digit
|
III - Radicand with whole & decimal numbers. Follows the same criteria.
Ex. IIIa:
________
√11.9025 = 3.45
c b A B C D E
1 1. 9 0 4 5
3 4 5
↑
1st digit
|
Ex. IIIb:
_______ √1.0404 = 1.02 c b A B C D E
… 1. 0 4 0 4
1 0 2
↑
1st digit
|
Ex. IIIc:
_________ √9.006001 = 3.001 c b A B C D E F G
… 9. 0 0 6 0 0 1
3 0 0 1
↑
1st digit
|