The ticket costs 109 - 5 = $<<109-5=104>>104 for each child.
So the ticket cost of the two children is 104 x 2 = $<<104*2=208>>208.
The couple needs to pay the regular price, so it's 109 x 2 = $<<109*2=218>>218.
Thus, the family needs to pay a total of 208 + 218 = $<<208+218=426>>426.
Therefore, their change is 500 - 426 = $<<500-426=74>>74.
#### 74