Retirement tax questions

Hi,

 

I've got a single lump sum  from Social Security that was paid to me in 2021. It covers ten months of 2020 (3 to 12/2020) and seven months of 2021 (1 to 7/2021). From the response above, it looks like I need to divide the total amount by total months, declare the ten month amount for 2020 as the lump sum amount and declare the seven months of 2021 as regular 2021 income? If so, how do I enter the 2021 portion of the lump sum as income?

 

Thanks,

Bernard