Basically when reading the value of a digit we start from the right.
Digits from the right to the left are named as follows:
units......>no zeros/digits after them
tens......> 1 zero/digit after the digit
hundreds.......> 2 zeros/digits after the digit
thousands......> 3 zeros/digits after the digit
ten thousands.......> 4 zeros/digits after the digit
hundred thousands.........> 5 zeros/digits after the digit
million........> 6 zeros/digits after the digit
Applying this concept to the above mentioned number, we will find that the period containing "913" is called nine hundred and thirteen thousands.