Deductions & credits

I really appreciate your help! Just to be clear for my brain. I would only enter the $400 difference since I already enter the  smaller amount paid on the 1098. For example, 1098 said $2000 in box 10 under other. But on the seller's statement it says $2400. I enter the 2000 on the 1098 deduction part and the 400 on additional taxes paid?