In the Water Margin
Jiang Jing is the fifty-third hero of Liangshan, born under the star Dihui (地会星). He comes from Tanzhou in Hunan and began life as a scholar, but after failing the examinations he gave up books for arms. He can handle a spear and staff and knows how to draw up troops, yet his real gift is arithmetic: the novel says he can tally ten thousand and a thousand more without missing the smallest fraction, so the rivers and lakes call him the Divine Calculator (神算子).
When the novel meets him he is the second chief of Mount Huangmen, along with Ou Peng, Ma Lin and Tao Zongwang. The four have heard of Song Jiang's name and his rescue at Jiangzhou, and when Song Jiang's party passes their mountain on its way back to Liangshan they come down not to rob it but to join it. At Liangshan Jiang Jing does what no one else can: he keeps the books, checking every bushel of grain and every string of cash that comes in or goes out. He is one of the few chiefs who come home alive from the war against Fang La. Asked what he wants, he chooses to go back to Tanzhou and live as a common man.
Key episodes
Coming down from Mount Huangmen. Song Jiang's men find the road through Mount Huangmen blocked by armed bandits and brace for a fight. Instead the four chiefs lay down their weapons and bow: they had meant to march to Jiangzhou to save him themselves.
Keeper of the accounts. At the grand assembly each chief is given his post. Chai Jin and Li Ying hold the treasury and granaries; Jiang Jing alone checks their figures, the one man on Liangshan whose job is to make the numbers add up.
Going home. After the victory over Fang La, the survivors are offered titles. Jiang Jing thinks of home and asks to return to Tanzhou as an ordinary subject.
