As the Sam He feng shui is also architectured on the numerology of River Map and Lo Shu with 8 trigrams, Sam He has its own i@nterpretation into specific formulas for application. For example, one of its formulas is named "later heaven trigram numbering total-of ten water dragron" method. This method is basically using the "na-jia" method and later heaven trigram numbering.
Trigram   Later heaven number     Map to HS/EB of 24 mountains
via Na-jia method
Qian        6                                         Jia
Kun          2                                          Yi
Li              9                                          Ren, Yin, Xu
Kan          1                                          Gui, Shen, Chen
Gen          8                                          Bing
Dui           7                                          Ding, Si, Chou
Zhen        3                                          Geng, Hai, Wei
Xun          4                                          Xin
Later heaven trigram numbering sum-of-ten water dragon method: 
The luopan mountain directions matching between the tomb facing and the water dragon, via their later heaven 8 trigram numberung, for achieving the  sum-of-ten.
e.g. Xun or Xin mountain (4) direction facing matches with the Qian or Jia mountain (6)  direction water = sum-of-ten.
Vice versa for the rests as per this method accordingly. 
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三合法 也有 合十為吉論。 例如, 《後天合十向水局》, 用上纳甲法和後天卦數。
巽辛向見乾甲水,  乾甲向見巽辛水。 （四六合十 ）
艮丙向見坤乙水,  坤乙向見艮丙水。 （二八合十 ）
震庚亥未向,  見兑丁巳丑水； 兑丁巳丑向,  見震庚亥未水。 （三七合十 ）
離壬寅戌向,  見坎癸申辰水； 坎癸申辰向,  見離壬寅戌水。 （一九合十 ） 
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