There were $$216$$ boys and $$153$$ girls at a party at first.  After an hour, $$37$$ children joined the party.  How many children were there at the party after an hour?  ~\uline{~~~~~~~~~~}~children were at the party after an hour. 
Overseas Competition->Knowledge Point->Word Problem Modules->Questions Involving Sum, Difference and Multiples->Problems Involving Sum and Difference