The text for the course is Van de Walle, John (2007). Elementary and Middle School Mathematics: Teaching Developmentally. 7th Edition. New York: Pearson. Chapters 8 and 10 (if needed)
View 6 student work samples and determine errors. You then need to explain what they did in words: what are they doing and why: is it an error or an alternate algorithm? Try to use place value language to describe why their work is consistently in error or consistently works.