有一位仙人，人称“上成公”，原籍河南郡密县(今河南密县)，生于东汉末年，后来成了仙，云游四方，飘无定处。由于不小心，失火烧了仙宮七间房子，上仙罚他到下界为寇谦作七年弟子，也是给他一个引渡寇谦得道的饥会。他化名成兴，表字广明，自言来自胶州（今山东半岛）在北魏初年，出现在伊川一带。学士殷绍，从他学《九章要术》，成为算学博士。后来，成兴又到关中，给寇谦的姨母家作仆人。
There was an immortal, known as "Shang Cheng Gong", originally from Mi County, Henan Province (now Mi County, Henan Province), born at the end of the Eastern Han Dynasty, and later became an immortal, traveling in the clouds, drifting around without a fixed place. Due to carelessness, fire burned down seven houses in the immortal palace, and the upper immortal punished him to be a disciple for Kou Qian in the lower world for seven years, which also gave him a hunger meeting to extradite Kou Qian to achieve Taoism. He assumed the name Chengxing, epithet Guangming, said he came from Jiaozhou (present-day Shandong Peninsula) in the early years of the Northern Wei Dynasty, appeared in the area of Yichuan. Yin Shao, a bachelor, learned the Nine Chapters of the Essential Art from him and became a doctor of arithmetic. Later, Chengxing went to Guanzhong and worked as a servant for Kou Qian's aunt's family.
有一天，寇谦去拜望他的姨母，向姨母禀告自己近来的情况。并说：为了躲避战乱，自己一个人，居住在南山，甚觉孤独寂寞，求姨母借用一个仆人作伴。姨母就让他在仆人中挑选。寇谦见成兴生得身材高大，力量过人，面貌憨厚，心地颖悟，虽然是个佣工，相貌却是不凡。就向姨母要了他，带回南山。
One day, Kou Qian went to visit his aunt and told her about his recent situation. He told his aunt about his recent situation and said that he was living alone in the southern mountains to avoid the war and felt lonely and isolated, so he asked his aunt to lend him a servant to keep him company. Auntie let him choose among the servants. Kou Qian saw Cheng Xing was born tall, strength, simple face, heart of wisdom, although it is a servant, but the appearance is extraordinary. He asked his aunt for him and brought him back to Nanshan.
有一天，寇谦在树荫下专心致志地演算《周髀算经》。成兴就在附近披荆斩棘，开垦荒地。一阵紧张劳动之后，来到树荫下歇息，一面看寇谦演算，看得非常认真。寇谦说：“干你的活去吧，看这干什么?”成兴听话地走开了。干了一阵子，又来观看，寇谦说：“干你的活去吧，这你不懂。”成兴听话地又走开了。一连几天，成兴看得越来越频繁，越来越认真，每次总是寇谦用话支使开去。
One day, Kou Qian was concentrating on the calculation of the Book of Arithmetic of the Zhou Thighs under the shade of a tree. Cheng Xing was nearby, cutting through the thorns and reclaiming the wasteland. After a period of intense labor, he came to rest under the shade of a tree and watched Kou Qian's calculations very attentively. Kou Qian said, "Do your work, what are you doing here?" Chengxing obediently walked away. After a while, he came back to watch again, and Kou Qian said, "Do your work, you don't understand." Cheng Xing obediently walked away again. For several days in a row, Chengxing watch more and more frequently, more and more seriously, every time always Kou Qian with words to support away.
不知为什么，几天来寇谦按照《算经》上的方法演算“七曜（日、月、五大行星）”的运行，总是同天象的实际不合，急得他拍脖子搔头皮，老大的不高兴。成兴看在眼里，就问寇谦：
I do not know why, a few days Kou Qian in accordance with the method of "calculation scripture" calculated "seven Yao (sun, moon, five planets)" operation, always with the actual sky does not match, so anxious that he patted his neck and scratch his scalp, the boss is not happy. Cheng Xing see in the eyes, asked Kou Qian:
“近来先生神色不好，可有什么不顺心的事？”
"Recently, Mr. looks bad, is there something wrong?"
“只为这几则算题。”寇谦拍打着书本说：“我学算术好几年了，自信技术还行，可就这七曜运行却难住了我。”说到这里，挥了挥手，“唉！给你说了也没用，干你的活去吧！”
"Only for these few arithmetic problems." Kou Qian tapped his book and said, "I've been learning arithmetic for several years now, and I'm confident that my skills are fine, but just this Seven Observations Run has been difficult for me." Speaking here, he waved his hand, "Ugh! It's useless to tell you, do your work!"
成兴说： “我看您演算好几天，倒是悟出来一点门道，咱俩试试看。”
Cheng Xing said: "I see you calculate a few days, but realized a little doorway, let's try."
寇谦看了看成兴，见他一本正经，不是在说大话，于是便和成兴一道，重新布筹。那时候，没有算盘，是用竹棒棒摆格子，叫做筹算。寇谦按成兴的指导，一一布筹。说来也怪，一道很复杂的算题，竟然轻易地解开了，而且方法很简便。寇谦有点不大相信，又重摆了一遍，通过验算，完全正确。不由得抬起头来，对成兴仔细打量了一番，觉得他有些来历。又询问了一阵子，觉得他讲的道理，既明白又深奥。便立起身来，要拜成兴为师，成兴连忙拦住，说： “这可使不得。你是主人，我是奴仆，刚才是偶有所得，不敢为师，但也颇爱算学，倒是请先生收我为弟子，也好一同切磋。”寇谦答应了。从此，二人志趣相投，关系融洽，山中日子过得倒也十分快活。
Kou Qian looked at Cheng Xing, saw that he was serious, not talking big words, so he and Cheng Xing together, re-planning. At that time, there was no abacus, it was a bamboo stick to set up a grid, which was called a chip counting. Kou Qian according to the guidance of Cheng Xing, one by one, cloth chips. Strangely enough, a very complicated math problem was easily solved, and the method was very simple. Kou Qian a little not quite believe, and again re-posed, through the check, completely correct. Can not help but raise his head, Cheng Xing carefully sized up some, think he has some history. And inquire for a while, feel that his reasoning, both understandable and profound. So he stood up, want to worship Cheng Xing as a master, Cheng Xing hastily stopped, said: "This can not be allowed. You are the master, I am a slave, just now is an occasional gain, do not dare to be a teacher, but also quite love arithmetic, but please Mr. accept me as a disciple, or also together with the sparring." Kou Qian agreed. From then on, the two have similar interests, harmonious relations, mountain days are very happy.
过了一段时间，关中地方又起战争。成兴对寇谦说： “先生有意学道，可惜这种学法不行，这种地方也不行，需要找一个僻静的处所。如果你愿意的话，我可以领你到名山圣地去走一走。”寇谦欣然同意，于是作了准备，二人一同来到华山，找了一处岩穴住下。成兴每天山前山后刨草根，摘野果．回来收拾一下作食物，这样，他们虽然没有吃粮食，可也不觉得饥饿。
After some time, there was another war in Guanzhong. Cheng Xing said to Kou Qian: "You are interested in learning Taoism, but unfortunately, this kind of learning method is not possible, nor this kind of place, you need to find a secluded place. If you are willing, I can lead you to the famous mountains and holy places for a walk." Kou Qian readily agreed, so preparations were made, and the two of them came together to Mount Hua and found a rocky cave to stay in. Cheng Xing every day in front of the mountain and back to dig grass roots, picking wild fruits. Back to pack for food, so that, although they did not eat food, but also do not feel hungry.
在华山住了多天，成兴又带寇谦来到嵩山。
In the Huashan live for many days, Cheng Xing and bring Kou Qian came to Songshan.
这嵩山居五岳之中，号称中岳。方圆数百里，又分太室、少室、缑山、阳城、婴梁、讲山、浮戏等峰区。每个峰区，危岩幽谷，各具特色，历朝各代，都不乏高士、上人，如王子乔、鬼谷子、壶公之流，就在这里隐居讲学，修道成仙。成公兴领着寇谦来到嵩山别岭。这嵩山别岭，就是北岭、北嵩山，古书上篆文“别”“北”二字相近，北岭混为别岭，也就是今天的方山、浮戏山。这里距密县很近，当年成兴修道的石洞还存在，就是现在被称为仙人洞的地方。这个洞穴，进深三重。成兴让寇谦住了第二重，自己住在第一重。第三重是秘室，一般人是进不去的。他们住在这里，每日除了讲经论道之外，就是采药炼丹，服食导引，熊颈鸟伸。渐渐练得身轻体柔，思想也比以前通灵彻悟得多了。
This Songshan in the five mountains, known as the middle mountain. Hundreds of miles in circumference, and divided into too room, less room, Gou Gou mountain, Yangcheng, baby Liang, speak of the mountain, floating theater and other peak areas. Each peak area, dangerous rocks and valleys, each with its own characteristics, through the ages, there is no lack of high priests, people, such as Prince Qiao, Gwigu Zi, the stream of pot Gong, in this hermitage lectures, cultivation and immortality. Cheng Gongxing led Kou Qian to Songshan Beiling. This songshan beiling, is the north ridge, north songshan, ancient books on the seal script "don't" "north" two words are similar, the north ridge is mixed with beiling, that is, today's square mountain, floating theater mountain. This place is very close to Mixian County, and the stone cave where Chengxing practiced Taoism still exists, which is now known as the Immortal Cave. This cave is three times deep. Cheng Xing let Kou Qian live in the second, and he himself lived in the first. The third level was a secret room that ordinary people could not enter. They lived here, every day, in addition to preaching and discussing the Tao, is to collect medicine and alchemy, take food guide, bear neck and bird stretching. Gradually practiced to light body, body soft, thought than before the spiritual enlightenment more.
不觉几年过去了。有一天成兴对寇谦说： “先生，我有点事，须要到别处去几天。我走以后，会有人给您送吃喝来的，您只管吃就是了。”
A few years passed. One day Cheng Xing said to Kou Qian: "Mr., I have something to do, have to go elsewhere for a few days. After I leave, someone will bring you food and drink, you just eat."
成兴离开以后，果然有人送吃的来了。寇谦打开食盒一看，哪里有什么食物?尽是些毒蛇、虿蝎，夹杂着恶臭的东西，吓得他连忙躲了出去。成兴回来，受到寇谦好一阵埋怨．成兴惋惜地说：“看来，先生无缘成为仙人，只好作帝王之师了。”原来，这是对寇谦的一次考验。
After Cheng Xing left, someone did bring food. Kou Qian opened the food box to see, where there is what food? All are some poisonous snakes, insects and scorpions, mixed with foul-smelling things, scared him quickly hide out. Cheng Xing came back, by Kou Qian a burst of complaints. Cheng Xing said regretfully: "It seems, Mr. not have the chance to become an immortal, but only as the emperor's teacher." Originally, this is a test for Kou Qian.
成兴与寇谦相处，前后不觉七年。一天，成兴告诉寇谦：“我们俩快要分手了，时间就在明天。我死之后，请您替我沐浴身体。有人来访，您要接待他，不能怠慢。”说罢，进入第三重洞穴，好久不见出来，等寇谦进去察看时，成兴已经死去多时了。寇谦十分悲痛，遵照遗嘱，为他沐浴净身，安排后事。第二天中午，寇谦正在守着成兴的尸体悲伤，忽然洞外来了两个邋遢化子，一人腋下夹了一卷破蓑衣，一人手中拄了一根枣木棍，声称要见成兴讨帐。寇谦正在要发脾气，想起了成兴“不能怠慢”那句临终遗嘱，便恭敬地把他们领到成兴的尸体旁边。两个化子争着把手中的东西投向成兴尸体。只见成兴一跃而起，披蓑持棍，一时金光耀眼，满室生辉，蓑衣变成金紫道袍，枣木棍变成玲珑宝杖，两个化子，也变成了两位仙童。欢天喜地的簇拥着成兴，越门而出，凌空而去。寇谦这才恍然大悟，原来成兴是一位神仙下凡。连忙跪倒，向空遥拜。
Cheng Xing and Kou Qian have been together for seven years. One day, Cheng Xing told Kou Qian: "We two are about to part, the time is tomorrow. After I die, please bathe my body for me. When someone visits, you must receive him and not be neglectful." Saying this, he entered the third cave and did not come out for a long time. When Kou Qian went in to inspect, Cheng Xing had already died for many hours. Kou Qian was very sad and followed the will, bathing and purifying him and arranging the aftermath. The next day at noon, Kou Qian is guarding Cheng Xing's body sadness, suddenly outside the cave came two scruffy chemical, one armpit clamped a volume of ragged straw raincoat, a hand on a date stick, claimed to see Cheng Xing to collect the bill. Kou Qian is to lose his temper, remembered the Cheng Xing "can not be slow" that dying will, they will respectfully lead them to Cheng Xing's body next to. The two chemists scrambled to throw what they had in their hands at Cheng Xing's corpse. Only to see Cheng Xing leaped up, wearing straw holding stick, a moment of golden light, full of glory, straw coat into gold and purple robes, jujube stick into exquisite staff, the two chemical, also turned into two fairy children. Joyfully flanked Cheng Xing, crossed the door and went out in the air. Only then did Kou Qian realize that Cheng Xing was an immortal. He quickly fell down on his knees and bowed to the air.
寇谦失去了好友，失去引导他修道成仙的师父，心中非常难过。以后每次向人称道成兴时，总要在当中夹入一个“公”字，称“成公兴”，以示尊重。
Kou Qian was saddened by the loss of his friend and master who had guided him to become an immortal. In the future, every time he talked about Cheng Xing, he would always put the word "Gong" in the middle of it and call himself "Cheng Gong Xing" to show his respect.
寇谦遵照成公兴师父的教导，在石洞中专心致志，研究道学、算法，从不懈怠，一直守了三年。三年中，他陆续收了几个徒弟，传授自己的道法、算法。
Kou Qian followed the teachings of Master Cheng Gongxing, in the stone cave to concentrate on the study of Taoism, algorithms, never slack, has been three years. During the three years, he took in several disciples one after another to teach his Taoism and algorithms.