In late winter 2020, the onset of the COVID-19 pandemic necessitated restrictions on travel, commerce, and public gatherings. In a time and place where there are no public spaces, how might we adapt our work? We wanted to design for families where they are, and that is at home. We value engagement over telling, and conversation over correctness. If we could not provoke wonder and discussion in public, we needed to provoke them in families’ homes. We settled on postcards, and asked ourselves, “What math can you elicit with a postcard?”and “What math can children do with a postcard?” Our first answer was that a postcard—when something is cut out from it—could be a frame for looking at the everyday world in a mathematical way. Next, we turned our attention to providing families the means for mathematical creativity: a Truchet Tiles postcard. This postcard consists of 12 colorful patterns. Our third postcard type is a conversation starter.