[Set 721,734,273 on Mr. Cube root]Zoom
[Japanese]
Today's example is also about actual solution of Cube root using abacus. The calculation becomes more complicated than previous example.
Today's example is simple - basic Triple-root method, root is 3-digits case and requires 9 as root in the middle of calculation. Please check the Theory page for your reference.
Cube root methods: Triple-root method, constant number method, 3a^2 method, 1/3-division method, 1/3-multiplication table method, 1/3-multiplication table alternative method, Multiplication-Subtraction method, 3-root^2 method, Mixing method, Exceed number method, Omission Method, etc.
Abacus steps to solve Square root of 721,734,273
(Answer is 897)
"1st group number" is the left most numbers in the 3-digits groups of the given number for cube root calculation. Number of groups is the number of digits of the Cube root.
721,734,273 -> (721|734|273): 721 is the 1st group number. The root digits is 3.
![]()
Step 1: Set 721734273. First group is 721.
![]()
Step 2: Cube number smaller than 721 is 512=8^3. Place 8 on D as 1st root.
![]()
Step 3: Place 721-512=209 on GHI.(-a^3)
![]()
Step 4: Place Triple root 3x8=24 on AB.
![]()
Step 5: Repeat division by triple root 24 until 4th digits next to 1st root.(/3a)
![]()
Step 6: 209/24=8 remainder 17. Place 8 on F.
![]()
Step 7: Place remainder 017 on GHI.
![]()
Step 8: 117/24=7 remainder 9.
![]()
Step 9: Place 7 on G.
![]()
Step 10: Place remainder 009 on HIJ.
![]()
Step 11: 93/24=3 remainder 21.
![]()
Step 12: Place 3 on H.
![]()
Step 13: Place remainder 21 on JK.
![]()
Step 14: Divide 87 on FG by current root 8. 87/8=10 remainder 7.
![]()
Step 15: Place 9 as 2nd root on E according to the calculation rule.
![]()
Step 16: Divide 87 on FG by current root 9. 87/9=8 remainder 15.
![]()
Step 17: Place remainder 15 on FG.
![]()
Step 18: Subtract 2nd root^2 from 153 on FGH. (-b^2)
![]()
Step 19: Place 153-9^2=072 on FGH.
![]()
Step 20: Multiply triple root 24 by remainder 72 on GH. 24X72=1728
![]()
Step 21: Replace 72 by 00 on GH.
![]()
Step 22: Add 1728 to 0021 on HIJK.
![]()
Step 23: It means place 0021+1728=1749 on HIJK.
![]()
Step 24: Subtract 2nd root^3 from 7494 on IJKL. (-b^3)
![]()
Step 25: It means place 7494-9^3=6765 on IJKL.
![]()
Step 26: Focus on triple root (ABC).
![]()
Step 27: Add 3x2nd root to triple root root on BC. Place 240+3x9=267 on ABC.
![]()
Step 28: Repeat division by triple root 267 until fixed position. (/3a)
![]()
Step 29: Divide 1676 on HIJK by triple root 267. Place 1676/267=6 remainder 74. Place 6 on G.
![]()
Step 30: Place 0074 on HIJK.
![]()
Step 31: 745/267=2 remainder 211
![]()
Step 32: Place 2 on H.
![]()
Step 33: Place remainder 211 on JKL.
![]()
Step 34: 211/267=7 remainder 24
![]()
Step 35: Place 7 on I.
![]()
Step 36: Place remainder 024 on JKL.
![]()
Step 37: 2437/267=9 remainder 34
![]()
Step 38: Place 9 on J.
![]()
Step 39: Place remainder 0034 on KLMN.
![]()
Step 40: Divide 627 by current root 89.
![]()
Step 41: 627/89=7 remainder 4. Place 7 on F as 3rd root.
![]()
Step 42: Place remainder 004 on GHI.
![]()
Step 43: Subtract 3rd root^2 from 49 on IJ. (-c^2)
![]()
Step 44: Place 49-7^2=00 on IJ.
![]()
Step 45: Subtract 3rd root^3 from 343 on MNO. (-c^3)
![]()
Step 46: Place 343-7^3=000 on MNO.
![]()
Step 47: Cube root of 721734273 is 897.
![]()
Final state: Answer 897
Abacus state transition. (Click to Zoom)
![]()
![]()
Next article is also about Cube root calculation (Triple-root method).
Related articles:
How to solve Cube root of 1729.03 using abacus? (Feynman v.s. Abacus man)
http://blog.goo.ne.jp/ktonegaw/e/cff5d6e7ecaa07230b9cc7af10b23aed
Index: Square root and Cube root using Abacus
http://blog.goo.ne.jp/ktonegaw/e/f62fb31b6a3a0417ec5d33591249451b
Please place your mouse on the buttons and click one by one. These are blog ranking sites.
[Japanese]
Today's example is also about actual solution of Cube root using abacus. The calculation becomes more complicated than previous example.
Today's example is simple - basic Triple-root method, root is 3-digits case and requires 9 as root in the middle of calculation. Please check the Theory page for your reference.
Cube root methods: Triple-root method, constant number method, 3a^2 method, 1/3-division method, 1/3-multiplication table method, 1/3-multiplication table alternative method, Multiplication-Subtraction method, 3-root^2 method, Mixing method, Exceed number method, Omission Method, etc.
Abacus steps to solve Square root of 721,734,273
(Answer is 897)
"1st group number" is the left most numbers in the 3-digits groups of the given number for cube root calculation. Number of groups is the number of digits of the Cube root.
721,734,273 -> (721|734|273): 721 is the 1st group number. The root digits is 3.

Step 1: Set 721734273. First group is 721.

Step 2: Cube number smaller than 721 is 512=8^3. Place 8 on D as 1st root.

Step 3: Place 721-512=209 on GHI.(-a^3)

Step 4: Place Triple root 3x8=24 on AB.

Step 5: Repeat division by triple root 24 until 4th digits next to 1st root.(/3a)

Step 6: 209/24=8 remainder 17. Place 8 on F.

Step 7: Place remainder 017 on GHI.

Step 8: 117/24=7 remainder 9.

Step 9: Place 7 on G.

Step 10: Place remainder 009 on HIJ.

Step 11: 93/24=3 remainder 21.

Step 12: Place 3 on H.

Step 13: Place remainder 21 on JK.

Step 14: Divide 87 on FG by current root 8. 87/8=10 remainder 7.

Step 15: Place 9 as 2nd root on E according to the calculation rule.

Step 16: Divide 87 on FG by current root 9. 87/9=8 remainder 15.

Step 17: Place remainder 15 on FG.

Step 18: Subtract 2nd root^2 from 153 on FGH. (-b^2)

Step 19: Place 153-9^2=072 on FGH.

Step 20: Multiply triple root 24 by remainder 72 on GH. 24X72=1728

Step 21: Replace 72 by 00 on GH.

Step 22: Add 1728 to 0021 on HIJK.

Step 23: It means place 0021+1728=1749 on HIJK.

Step 24: Subtract 2nd root^3 from 7494 on IJKL. (-b^3)

Step 25: It means place 7494-9^3=6765 on IJKL.

Step 26: Focus on triple root (ABC).

Step 27: Add 3x2nd root to triple root root on BC. Place 240+3x9=267 on ABC.

Step 28: Repeat division by triple root 267 until fixed position. (/3a)

Step 29: Divide 1676 on HIJK by triple root 267. Place 1676/267=6 remainder 74. Place 6 on G.

Step 30: Place 0074 on HIJK.

Step 31: 745/267=2 remainder 211

Step 32: Place 2 on H.

Step 33: Place remainder 211 on JKL.

Step 34: 211/267=7 remainder 24

Step 35: Place 7 on I.

Step 36: Place remainder 024 on JKL.

Step 37: 2437/267=9 remainder 34

Step 38: Place 9 on J.

Step 39: Place remainder 0034 on KLMN.

Step 40: Divide 627 by current root 89.

Step 41: 627/89=7 remainder 4. Place 7 on F as 3rd root.

Step 42: Place remainder 004 on GHI.

Step 43: Subtract 3rd root^2 from 49 on IJ. (-c^2)

Step 44: Place 49-7^2=00 on IJ.

Step 45: Subtract 3rd root^3 from 343 on MNO. (-c^3)

Step 46: Place 343-7^3=000 on MNO.

Step 47: Cube root of 721734273 is 897.

Final state: Answer 897
Abacus state transition. (Click to Zoom)


Next article is also about Cube root calculation (Triple-root method).
Related articles:
How to solve Cube root of 1729.03 using abacus? (Feynman v.s. Abacus man)
http://blog.goo.ne.jp/ktonegaw/e/cff5d6e7ecaa07230b9cc7af10b23aed
Index: Square root and Cube root using Abacus
http://blog.goo.ne.jp/ktonegaw/e/f62fb31b6a3a0417ec5d33591249451b
Please place your mouse on the buttons and click one by one. These are blog ranking sites.


