Finger speed algorithm

Chapter 4 Addition and Subtraction (2)
3624—2389时，左无名指位直接掐去2；右无名指位掐人3的凑数2，掐去5：右拇指位：前一指位（右无名指位）掐去1，本指位掐入8的补数2；右食指位：前一指位（右拇指位）掐去1，本指位掐入5，掐去9的补数1的凑数4。

1235+8497时，左无名指位直接掐入8；右无名指位掐入5，掐去4的凑数1；右拇指位掐去9的补数1，向前一指位（右无名指位）进1；右食指位掐入7的补数3的凑数2，掐去5，向前一指位（右拇指位）进1。

Mantra addition and subtraction:

From 3624 to 2389, for the left ring finger, two to two; for the right ring finger, three up, two to five; for the right thumb, eight back and one for two; for the right index finger, nine back and one for five and four.

When 1235+8497, left ring finger position, eight up and eight; right ring finger position, four down five to one; The method is the same as integer addition and subtraction.

Example 4, 3866.27+4387.96=8254.23.

指算过程：先在左无名指（千位）、右无名指（百位）、右拇指（十位）、右食指（个位）、左食指（十分位）、左拇指（百分位）上依次布入3、8、6、6、2、7；然后，在左无名指、右无名指、右拇指、右食指、左食指、左拇指上依次加上4、3、8、7、9、6，得到结果8254.23。

The operation process of the two methods is as follows:
No formula plus:
左无名指位掐入5，掐去4的凑数1；右无名指位直接掐去3的补数7，向前一指位（左无名指位）进1；右拇指位掐入8的补数2的凑数3，掐去5，向前一指位（右无名指位）进1；右食指位掐入7的补数3的凑数2，掐去5，向前一指位（右拇指位）进1；左食指位掐去9的补数.1，向前一位（右食指位）进1；左拇指位掐人6的补数4的凑数1，.掐去5，向前一指位（左食指位）进1。

Mantra plus:
Left ring finger position, four down five to one; right ring finger position, three to seven to one; right thumb position, eight to three to five to one; right index finger to seven to two to five to one; left index finger to nine to One into one; left thumb position, six up, one down, five into one.

Example 5, 53784.3—36297.8=17486.5
指算过程：先在左拇指（万位）、左无名指（千位）、右无名指（百位）、右拇指（十位）、右食指（个位）、左食指（十分位）上依次掐入5、3、7、8、4、3；然后，在左拇指、左无名指、右无名指、右搏指、右食指、左食指上依次减去3、6、2、9、7、8，算指上，得差17486.5。

The calculation process of the two methods is as follows:

No formula minus:
左拇指位掐人3的凑数2，掐去5；左无名指位向前一指位（左拇指位）借1，本指位掐人5，掐去6的补数4的凑数1；右无名指位直接掐去2；右拇指位向前一指位（右无名指位）借1，本指位掐入9的补数1；右食指位向前一指位（右拇指位）借1，本指位掐入5，掐去7的补数3的凑数2；左食指位向前一指位（右食指位）借1，本指位掐人5，掐去8的补数2的凑数3。

Mantra minus:
Left thumb position, three up, two to five; left ring finger position, six back one back five back one; right ring finger position, two back two back; right thumb position, nine back one back one back; right index finger position, seven back one back five back Go two to the left index finger, eight back one back five go two.

Usually in the calculation, sometimes encounter the arithmetic problem that the minuend is less than the subtrahend, we often get the negative number by exchanging the minuend and the subtrahend and subtracting them.It is more troublesome to change the order in this way. You can borrow "1" on the previous finger of the subtrahend, and then subtract the original subtrahend from the sum of the virtual borrowed "1" and the minuend, and the negative complement of the difference ( In a broad sense, the complement number means that the sum of two numbers is the positive integer power of 10, that is, when 10 or 100, : 1000, ..., the two numbers complement each other), which is the difference between the original two numbers.

例6、286—479=286+（1000）—479：1286—479；—1000：V=807，—1000；—，WP，——193（807的负补数即一193）

指算过程：先在右无名指（百位）、右拇指（十位）、右食指（个位）上依次布入2、8、6；然后在前一指位（左无名指位）虚借“1”，得1286，再在右无名指、右拇指、右食指位上依次减去4、7、9，得差807；最后脑算出807的补数为193，在193前面添上负号为—193，—193就是286—479=—193。

In the calculation, if there is not enough subtraction in the previous addition and subtraction of multiple strokes, you can also borrow "1" to subtract it. If you add a few strokes later, you can return the borrowed "1". The difference you want is Positive value.Borrowing subtraction just creates conditions to transform non-subtractable into able-subtractable.

例7、286—479+231=286+（1000）—479+231—1000=1286—479+231—1000=807+231—1000=1038—1000=38。

计算286—479时可参照例6，后一段，先在右无名指、右拇指、右食指位上依次布入8、0、7；然后从右无名指位起，在各算指上依次加上2、3、1。算指上，得到数1038；再从1038中减去千位上虚借的“1”（1000），算指上得到的结果为38。

Exercise [-]

1. What is the algorithm of multi-digit addition and subtraction?
2. Use arithmetic to calculate the following questions (there is no operation symbol in front of the number to indicate addition).

26, 74, 38, 43, 97.

48, 62, 88, 68,—43.

57, 19, 67,—29, 32.

61, 83, 52, 45, 78.

89, 92, 79, one 36, one 65.

39, 86, 64, 74, 59.

58, 37, 26,—26, 78.

67, 52, 95, 98,—34.

24, 65, 33,—83, 82.

46, 34, 70, 64,—57.

93, 46, 31, 99, 67.

49, 32, 78,—36, 98.

56, 54, 93, 58,—51.

35, 17, 44, 63, 13.

80, 29, 20, -47, -74.

67, 75, 52,—14, 45.

22, 90, 87, 82,—18.

94, 49, 18, 76, 93.

85, 73, 69, 97, 64.

30, 86, 17, one 49, one 87.

62, 37, 92, 68, 18.

58, 14, 54, -531, -40.

19, 60, 35, 34, 52.

27, 28, 83, -25, -36.

19, 28, 98, 68, 89.

47, 90, 17, 39, 13.

58, 46, 74, one 41, one 64.

70, 15, 52, 97, 70.

96, 83, 26, -55, -48.

34, 37, 65, 74, 26.

85, 62, 30, 86, 95.

21, 24, 83, 63, 37.

62, 71, 41, 20, 52.

53, 59, 19, 16,—78.

81, 95, 18, 63, 94.

59, 49, 96, 48,—39.

90, 20, 39,—39, 63.

67, 53, 72, 76,—45.

18, 38, 27, 87, 86.

44, 14, 60, 30,—58.

73, 87, 53,—14, 70.

32, 78, 81, 92,—17.

97, 62, 45, 25, 29.

26, 86, 64, 51, 37.

184, 921, 418, 329, 807.

578, 278, 852, 746, 594.

207, 395, 374, -613, -468.

453, 604, 160, 894, 935.

735, 867, 983, -278, -739.

549, 843, 764, 921, 859.

657, 467, 259, 853, 674.

320, 635, 640,—369, 367.

824, 372—, 497, 578,—490.

438, 284, 948, 745, 278.

746, 829, 683, 798, 839.

538, 163, 195, 234,—480.

374, 274, 347, 370, 675.

260, 658, 968, 986, 743.

698, 942, 209, -459, -598.

853, 780, 726, 647, 167.

487, 491, 572, -523, -956.

947, 187, 798, 892, 739.

785, 658, 310, 589, 407.

138, 269, 647, -627, -384.

469, 824, 456, 974, 853.

804, 715, 582, 264, 518.

256, 403, 209, 458, 926.

593, 346, 965, -735, -642.

974, 396, 857, 584, 625.

519, 427, 648, 721,—378.

185, 935, 735,—148, 984.

793, 708, 962, 290, 769.

806, 579, 174, one 465, one 593.

468, 841, 203, 379, 156.

620, 213, 481,—653, 431.

342, 654, 396, 937, 812.

257, 180, 519,—802, 240.

931, 862, 420, 196, 157.

634, 148, 916, 276, 351.

857, 976, 385, 580, 748.

241, 397, 160, -602, -480.

568, 259, 524, 954, 823.

193, 804, 291, -143, -502.

785, 480, 708, 298, 679.

970, 865, 872, 861, 294.

429, 531, 637, 715, 915.

312, 623, 443, 329,—167.

706, 912, 659,—237, 436.

7189.

9253, 6759, 1486, — 1789.

1432.

3978, 2847, 8573, — 3891.

8695.

8427, 5836, 7089, 9248, 4573.

5748, 1396, 4625.

8239, 7854, 8769.

2584, 5962, 1548.

6173, 3749, 6237.

1465, 9218, 3984.

8563, 1892, 4863.

4079, 5687, 5472.

7635, 9534, 9137.

1958, 8249, 1780.

3246, 4358, 6549.

5480, 7120, 3294.

6724, 6073, 2951.

6852, 2857, 3479.

4319, 8762, 6143.

8907, 4395, 8634.

2438, 9670, 2907.

7543, 5184, 5726.

5691, 1908, 4891.

9126, 3546, 7258.

1847, 6273, 4729.

7524, 3648, 4513.

5679, 8759, 2954.

6192, 4132, 8170.

2481, 5391, 1836.

4708, 9417, 6041.

8936, 1504, 3298.

9053, 7025, 5407.

3265, 2860, 7362.

5310, 4986, 9685.

2973, 9547, — 1394, — 6789.

5782, 7458.

8257, -2962, -7638, 1834,

7098, 9463. 5149, 5784.

—3956, —7496, 6834, 8659.

One 8272, One 1972, One 1583, One 4237.

—2765, 6315, 8105, 5712.

—2617, —3923, 1876, 6457.

—3254, 9108, 7923, —7654.

—8739, 4579, 4082, —1386.

8041.

—9830, —8462, 1259, 4136.

7682, 5654, -4796, -7801.

3503, 6920, 2168, 3275.

6315, 2593, — 1974, — 4789.

3294, 5914, 7613, 2389, 8746.

7518, 2638, 1549, 8745, 4905.

1467, 6429, 5368, one 3826, one 7158.

8142, 1507, 9450, 4108, 1380.

2039, 9280, 2731, 6473, 2897.

6870, 3841, 6092, 7051, 9413.

9351, 7052, 3804, -1932, -5629.

5603, 4375, 8125, 9260, 6031.

4785, 8163, 4276, -5614, -3264.

7926, 2796, 1987, 8597, 4572.

18, 39, 758, 903, 28.

279, 581, 13,—27, 836.

65, 74, 629, 538,—79.

436, 826, 46, 84, 145.

53, 98, 187, 356, 94.

625, 974, 5319, 8049, 439.

1402, 2519, 843,—754, 6018.

387, 163, 4208, 987, 367.

5139, 3786, 586,—1002, 672.

268, 407, 9174, 536,—4856.

72, 58, 217, 304, 719.

389, 179, 48, -189, -24.

24, 36, 826, 78, 53.

736, 942, 673, 916, 282.

91, 83, 29,—23, 96.

407, 67, 35, 561,—48.

68, 594, 794, 435, 867.

427, 5127, 7182, 8704, 126.

1762, 834, 549,—217, 5098.

239, 2385, 4276, 3529,—947.

3698, 678, 694,—486, 1583.

351, 192, 321, 9632,—359.

483, 9046, 6857, 2873, 3674.

9806, 753, 265, 748, 6712.

29, 604, 917, 703, 93.

437, 18, 69,—85, 807.

780, 572, 54, 176, 69.

63, 380, 871, 490, 246.

296, 96, 283, 804, 380.

58, 139, 90, 185, 52.

815, 45, 508, 296, 38.

41, 761, 36,—542, 721.

72, 87, 625, -24, -74.

904, 423, 342, 617, 615.

5083, 765, 403, 748, 6841.

197, 1802, 8059, 364, 597.

304, 326, 274, 8059, 4309.

4712, 680, 690,—820, 3754.

849, 7038, 3825, 6192,—7218.

231, 917, 187, 903, 436.

2568, 479, 5812, -2417, -920.

620, 9143, 4361, 71, 5072.

3956, 591, 536, 635, 1683.

475, 6254, 7948-43, 9586, 8165.

(End of this chapter)