While a government budget determines how taxpayers' money is allocated to various programs and stakeholders that compete for limited resources, the extensiveness and complexity of the budget and its process hinder taxpayers from understanding the budget information and participating in the public discussion. To engage taxpayers in the public discussion around budgetary issues, we leverage news articles containing budgetary information for design opportunities. We present Factful, a web-based annotative article reading interface that enhances the article with fact-checking support and contextual budgetary information by processing open government data. In our lab study, participants using Factful discussed more critically with more fact-based supporting statements. They built a rich context surrounding the relevant budget facts beyond what was presented in the article. Factful presents a simple yet powerful model for supporting fact-oriented budgetary discussions online by leveraging open government data.