How many position in channel 4s ratings a have February 24, 2010 as the original airing on channel 4?
create table table_22170495_6 (position_in_channel_4s_ratings_a varchar, original_airing_on_channel_4 varchar, PRIMARY KEY (position_in_channel_4s_ratings_a))
select count(position_in_channel_4s_ratings_a) from table_22170495_6 where original_airing_on_channel_4 = "february 24, 2010"