Full article: Early algebraic thinking and the US mathematics standards for grades K to 5 / El pensamiento algebraico temprano y los estándares matemáticos en la Educación Primaria (6–12 años) en Estados Unidos
![Amazon.com: Defenders Epic Collection: The Six-Fingered Hand Saga (Epic Collection: Defenders): 9780785195993: Perlin, Don, Bingham, Jerry, Ditko, Steve, Zeck, Mike, DeMatteis, J.M., Barr, Mike W., Gruenwald, Mark: Books Amazon.com: Defenders Epic Collection: The Six-Fingered Hand Saga (Epic Collection: Defenders): 9780785195993: Perlin, Don, Bingham, Jerry, Ditko, Steve, Zeck, Mike, DeMatteis, J.M., Barr, Mike W., Gruenwald, Mark: Books](https://m.media-amazon.com/images/I/61Zxbu2hnfL._AC_SY780_.jpg)
Amazon.com: Defenders Epic Collection: The Six-Fingered Hand Saga (Epic Collection: Defenders): 9780785195993: Perlin, Don, Bingham, Jerry, Ditko, Steve, Zeck, Mike, DeMatteis, J.M., Barr, Mike W., Gruenwald, Mark: Books
![Amazon.com: Defenders Epic Collection: The Six-Fingered Hand Saga (Epic Collection: Defenders): 9780785195993: Perlin, Don, Bingham, Jerry, Ditko, Steve, Zeck, Mike, DeMatteis, J.M., Barr, Mike W., Gruenwald, Mark: Books Amazon.com: Defenders Epic Collection: The Six-Fingered Hand Saga (Epic Collection: Defenders): 9780785195993: Perlin, Don, Bingham, Jerry, Ditko, Steve, Zeck, Mike, DeMatteis, J.M., Barr, Mike W., Gruenwald, Mark: Books](https://images-na.ssl-images-amazon.com/images/I/61+u9NoHcdL._AC_UL600_SR600,600_.jpg)