In Numbers am I able to simultaneously input to multiple spreadsheets in the same workbook?

You cannot. You cannot select tables from different sheets at the same time or select more than one sheet at a time and, even if all tables were on one sheet, there is no feature to allow you to modify a formula in more than once cell in one table at a time. For ten tables, I think Copy/Paste is your best option for changing formulas and text. Formatting changes will go along with copy/paste but if you want to copy/paste only the format you can use Copy Style and Paste Style.

Hi Emma,

While you can't directly enter the same data into all 10 tables at the same time, you can have nine of those tables gather the same data from the one in which you are making the data entries.

From your description, it appears you are entering each of the same data items into a fixed location on each table, then processing that data with a set of formulas specific to each of the tables.

I'll set up one spreadsheet that does what I want it to do,

In Numbers, do exactly the same thing. Using Numbers' vocabulary, 'set up one table on the first Sheet that does what you want it to do. Replace this table's default name (most likely "Table 1") with a name that will be distinct from the names of all other tables in the document.

Then Copy that Table, add a second Sheet to the Document, delete the Table that is automatically placed on that sheet by Numbers, and Paste the copy of the first table on the new Sheet. Rename the pasted table, again using a name distinct from all other tables in the document. (The name or two letter postal symbol of the state to which this table's calculation apply would work).

Duplicate this table eight times, then place each coy on a separate new Sheet, and rename each table.

If the formulas entered on the first table are suitable for all the tables, your Spreadsheet (document) should now be ready for use. Otherwise make the necessary edits to each of the tables to fit the actual circumstances.

When all is ready, lock each of the tables except the first one, which must be left unlocked in order to enter new data. Locking te others does not affect their ability to gather data from the first table, but will serve to protect the locked tables from accidental changes.

In use, replacing the data in the data entry cells on the first table will cause the rest of the tables to pick up that new data and do the calculations.

Regards,

Barry

Edit the data cells on this table to replace each of the data values that will be common to all tables to a formula referencing the same cell on the first table.