"Three hundred" in Engpsh is spelled "three hundred."
This number is formed by combining the number "three" and the word "hundred." In Engpsh, the word "hundred" is used to indicate a value of 100. So, "three hundred" means 300.
Examples:
The number of pages in the book is three hundred. (这本书有三百页。)
I need to earn three hundred dollars by next month. (我下个月需要挣三百美元。)
The population of the city is around three hundred thousand. (这个城市的人口大约是三十万。)