I agree with you that the blank numerators in the example you provide do not represent space that the reader needs to fill.
Is it possible that your electronic file is not showing numerators, but the hard copy print does show them?
I ask because I believe I found a print representation of the text you are transcribing that includes your missing numerators. The following link leads to an electronic representation of what appears to be part of the text you are transcribing.
I found the site above by doing a Google search for "3. write the number on a place value chart. Then write it in expanded form using fractions or decimals to express" (with the parentheses included so that the search would be for those words exactly).
If the above does not answer your question, please do not hesitate to let me know.
Thank you for your time, and perseverance.