After you file

@kirch - Line 28 should be $3,000 as a result of the amendment.

 

How much did the IRS reduce your tax return by already?  That adjustment would reduce the $2750.  So $2750 less the IRS adjustment should be in Column A of the 1040-X.  Then Column C should be $3,000.  The difference goes in Column B.

 

The benefit is $3,000 for each child between the ages of 6 and 17 years old.