Title: La fortaleza de la calle cuatro
Description: Building a fort in the backyard, a grandfather and granddaughter get help from six simple machines: lever, pulley, inclined plane, wheel and axle, screw, and wedge.
Subjects: Building, Stories in rhyme, Grandfathers, Machinery, Spanish language materials, Simple machines, Fiction, Children's fiction, Building, fiction, Machinery, fiction, Grandparents, fiction