Can you Fill multiple rows simultaneously?

[Greener_Power1]

Hi, 

We're trying to apply a decimal value located in row 1 of a table to multiple rows below in order for us to adjust prices. 

We can do this via the google sheet using the old = sum method. but this is a slow, and doesn't provide instant returns visually within the app. 

Just curious if it's possible to apply a value to multiple rows based of a selection on 1 row. 

Thanks.