Place values are determined by the position of a digit in the number multiplied by 10 for each digit it has to its right.
Since there are two "5" digits in the number, let us break them down to their respective place values.
1.) 5: one's place: 5
2.) 5: hundred's place: 5 x 10 x 10 = 500
Adding the place values:
500 + 5 = 505
Therefore the sum is 505.