You cannot directly convert Numbers spreadsheets (.numbers) to Word documents (.docx) files. At best, you can find some work around that will allow you to copy and paste the tables from the spreadsheet to your document, but this may require some knowledge and post formatting.
Some online conversions supposedly support this conversion, but the results may not be what you were looking for. In most cases it will be just tables put directly in the document without any formatting.Open NUMBERS file Open DOCX file
An on-line version of Pages, Numbers, and Keynote