200 in words

Incorrect use of capitalization
 

When writing numbers in words, there is no need to add writing in capital letters unless it is at the beginning of a sentence

Spelling mistakes

Students tend to make spelling mistakes always, so to avoid it, try to memorize it. Some common spelling mistakes for the word hundred are hundred, hundred, hundreds, etc. 
 

 Formatting errors
 

Mixing up numbers and words is again a common mistake. For example one apple and 2 chocolate, instead, we should write 1 apple and 2 chocolate.
 

Using unnecessary hyphens
 

Adding hyphens in between is another mistake children tend to make again. Hyphens are only used while writing compound numbers. 
 

Incorrect use of the word and
 

Adding and after writing a place value is a mistake. But in American English, when we write numbers in words, we won't add and. In British English it is written as two hundred and ten, whereas in American English it is written as two hundred ten.
 

Incorrect use of capitalization
 

When writing numbers in words, there is no need to add writing in capital letters unless it is at the beginning of a sentence