If you are using the desktop TurboTax software you can see the Tax Smart Worksheet in forms mode. It's between lines 15 and 16 in the first section of the "Form 1040 or Form 1040-SR Worksheet." I don't think there is any way to see the Tax Smart Worksheet in TurboTax Online because there is no way to print the "Form 1040 or Form 1040-SR Worksheet." As far as I know it's not included in the PDFs from TurboTax Online.
But it's not clear what you mean by "that number." Are you trying see how the amount on Form 1040 line 15 was calculated? The Tax Smart Worksheet will not show you that. The Tax Smart Worksheet shows which of 7 possible methods was used to calculate line 16. Line 15 is just your Adjusted Gross Income (AGI) on line 11 minus the deductions on lines 12 and 13.