Hello, thank you in advance for your help!

I know that the correct answer is $14,400 but please explain the solution steps in detail!

At the end of 2018, Hauke Company purchased 6,000, $1,000, 9% bonds. The carrying value of the bonds at December 31, 2018 was $5,880,000. The bonds mature on March 1, 2023, and pay interest on March 1 and September 1. Hauke sells 3,000 bonds on September 1, 2019, for $2,964,000, after the interest has been received. Hauke uses straight-line amortization. The gain on the sale is