Hi ​@Kyle M 

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You may have to use a Code step to do the math operation: https://zapier.com/apps/code/help

Try using the AI in the Code step to generate the custom code for you: https://help.zapier.com/hc/en-us/articles/15666688064013-Generate-a-Code-step-using-AI-Beta

In your screenshot it looks like you’re sending the row numbers to update starting at row 21 from step 12. Formatted Rows Row.

You’ll need to edit the output here either as Troy suggests by code or through a formatter into step 12. To ensure that the row number starts with row 2. 

In Python it would be a simple case of creating and returning a list of the row numbers. 
 

last_row_number = 10 #  this can be replaced by input from another step


# Generate the list of numbers starting from 2 to last row

number_list = list(range(2, last_row_number + 1))


# Return the result

output = {"number_list": number_list}

Hello ​@Kyle M!

Did the Code step Troy and Badger suggested do the trick? Keen to hear if it worked for you! Let us know if you’re stuck—happy to assist further.