What do the notations on the 1900 US census mean?

I also think they represent later action.  I received this response from a NARA staff member:

>This is in response to your inquiry to the National Archives regarding the numbers written on various censuses.

Often, these numbers were data summaries used by Census Bureau tabulators to compiled statistical information. Much of this statistical information can be found on the Census Bureau's website at https://www.census.gov/prod/www/decennial.html. <