Writing prompt: Shi Maguang

Student essay:
Shi Maguang is a famous people in Chinese history, there is a story about his childhood.
When he was seven, he played the hide-and-seek with his friends in the garden. Suddenly a boy fell into a water-filled tank, so children was scared to cry, some of other went for help.
At that time, only Shi Maguang very dispassionate, he asked the children to crash a big stone to the tank. By the crash from stone, the tank broken and the boy who fell into tank pour out. Adult was surprised to Shi Maguang and commended his wisedom.
I was so surprised that Shi Maguang's wisedem and dispassionate. Shi Maguang was a wise man,was't,he?

Corrected essay:
Si Maguang is a famous person in Chinese history. There is a story about his childhood.
When he was seven, he played hide-and-seek with his friends in the garden. Suddenly a boy fell into a water-filled tank, so the children were scared and started to cry. Some of the others went for help.
At that time, only Si Maguang was very dispassionate. He asked the children to crash a big stone into the tank. By the crash from the stone, the tank broke and the boy who fell into the tank poured out. The adults were surprised by Si Maguang and commended his wisdom.
I was so surprised by Si Maguang's wisdom and dispassion. Si Maguang was a wise man, wasn't he?