A 2nd grade student shared an algorithm for subtraction that was learned at home. This provides a great opportunity to make sense of mathematics! With a focus on place value, the algorithm can be made sense of by our students. The PDF Pencast simply explains the algorithm...share it in class and use it as a context to make sense of math, develop number sense, focus on place value. NOTE: Adobe Reader DC (or equivalent) is needed to view the "video" aspect of this pencast PDF.