Rows created by user typing in a value

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We are setting up a testing sheet.  This sheet will need a certain number of rows in a formatted table based upon a value based upon a basic formula.  We are taking 2% of the product produced and perform testing.  So if we have 100 units we will test 2.  If we have 10,000 we will test 200.  When the  testing number (the 2% of the product) is calculated we need to have that many rows created in the formatted table.  Is there a way to have this done?