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_42840 ( "Team" text, "Tries for" real, "Tries against" real, "Try diff" text, "Points for" real, "Points against" real, "Points diff" text )

### Question ###
How many points against has team Cardiff had when there were less than 7 tries?

### Accurate SQL ###

SELECT COUNT("Points against") FROM table_42840 WHERE "Team" = 'cardiff' AND "Tries against" < '7'