Reading Latin poses many difficulties for English speakers, because they are accustomed to relying on word order to determine the roles of words in a sentence. In Latin, the grammatical form of a word, and not its position, is responsible for determining the word's function in a sentence. It has proven challenging to develop pedagogical techniques that successfully draw students' attention to the grammar of Latin and that students find engaging enough to use. Building on some of the most promising prior work in Latin instruction-the Michigan Latin approach--and on the insights underlying block-based programming languages used to teach children the basics of computer science, we developed Ingenium. Ingenium uses abstract puzzle blocks to communicate grammatical concepts. Engaging students in grammatical reflection, Ingenium succeeds when students are able to effectively decipher the meaning of Latin sentences. We adapted Ingenium to be used for two standard classroom activities: sentence translations and fill-in-the-blank exercises. We evaluated Ingenium with 67 novice Latin students in universities across the USA. When using Ingenium, participants opted to perform more optional exercises, completed translation exercises with significantly fewer errors related to word order and errors overall, as well as reported higher levels of engagement and attention to grammar than when using a traditional text-based interface.