Cifras y Teclas is a Spanish-language mathematics outreach blog created by David Orden, a professor of applied mathematics at the University of Alcalá. Its aim is to make mathematics approachable, enjoyable, and relevant by exploring the subject from varied perspectives and connecting it with other fields. The blog invites readers to learn together, share what they know, and discover the mathematics behind familiar ideas and everyday observations.

Its articles cover a broad range of topics, including algebra, geometry, statistics, logic, mathematical history, computing, education, research, and recreational mathematics. Posts combine explanations and curiosities with puzzles, examples, and cultural references, drawing on music, images, and real-world situations to spark interest. The site also features reader comments, an archive of past articles, and categories that help visitors browse subjects. Cifras y Teclas offers educational and informational content rather than commercial products or services, and encourages readers to follow its updates through social media.