I had to solve this question by finding out how many girls                                                                     were at the camp and there was 47 boys out of 82 so
i used a number liner to figure it out at the end there was
35 girls.

Grouping within 100/1000

                                           we are learning groups within 100/1000 so what we did
                                        was we had to figer out what something + something =1000 or 100
                                          for esample 35+65=100.