A mark for an empty place

You mean two hundreds, no tens and five ones. You write a 2, then a 5. That reads as 25. How can you show the empty tens column?

Rule: A zero holds a column. Remove it, and the number becomes a shorter number.

Without the 0, the 2 moves from hundreds to tens.

With no zeros, six numbers up to 9,999 all read as 25. They are 25, 205, 250, 2005, 2050 and 2500.