Not any more
It is common to do so, but not good form. For example, the number 1,097 should be written "one thousand ninety seven" not "one thousand and ninety seven". Similarly, the number 1,197 should be written "one thousand, one hundred ninety seven" not "one thousand, one hundred and ninety seven.
There are a number of situations which would be inappropriate to use a comma in. The common ones include when breaking a sentence and when stating number of items among others.
What are all the names of a comma in a number
A number cannot be turned into a comma which is a punctuation symbol.
The comma is used to separate similar words. 2011 is a number and January is 'text'. Therefore no comma is needed. But you would want to use a comma to separate two numbers. Hence January 11, 2011.
The comma goes after the word 'because' when it is used at the beginning of a dependent clause, separating the clause from the main clause. For example: "I stayed inside, because it was raining."
Yes, a comma should be used after "which" when it introduces a nonrestrictive clause in a sentence.
No. After the word and comma can not be used, as it is grammatically inappropriate to use comma after conjunctions such as and, which are called coordinate conjunctions.
Yes, you should use a comma before "Jr." when writing a person's name to separate the person's last name from the suffix. For example, "John Smith, Jr."
No, a comma is not necessary.
after the third number
no
no