Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_53396 ( "English Name" text, "Simplified" text, "Traditional" text, "Pinyin" text, "Hakka" text, "Area" real, "Population" real, "Density" real )

### Question ###
What's the sum of the population for the place simplified with an area smaller than 2,879?

### Accurate SQL ###

SELECT SUM("Population") FROM table_53396 WHERE "Simplified" = '上杭县' AND "Area" < '2,879'