Claude works as a teacher during the year at the local high school. He also prepares taxes on a part-time basis. During 2019, Claude earned $84,800 from his job as a teacher. He also earned $12,000 preparing taxes from January to April 2019. He operates his tax preparation business as a sole proprietorship. Claude estimates that he will owe $2,036 more in income taxes for 2019. Explain what Claude should do so that he does not incur any underpayment penalties.