Guessing from the verbiage this is Schwab. The supplemental details in the back is usually covered in the 1099s - check your 1099-B for this cusip you should have a line for the maturity with an AMD Amount in Box 1f for the $100, proceeds $1000 and cost $900. The AMD adjustment should zero out the gain/loss and flip the $100 to your Schedule B as ordinary income.
If you're seeing something different pls provide more info about what's showing on your 1099-B.
If you enter as sales summary the adjustment will trigger a need to send your 1099-B to the IRS, if you hit this suggest entering this item as "one by one" which will feed Form 8949, and remove the amounts from your sales summaries so the Schedule D is whole, that should remove the need to mail anything.
Not a CPA/Expert just my 2 cents.
