My daughter brought home a math test today and the teacher deducted 3 points because she SHOWED her work. Her work was correct and her answer was correct, but the teacher felt she should have done the work in her head since it was a factor of 10 problem. This is ridiculous because we drill it into our students' and children's heads to write everything down for partial credit. The teacher herself wrote a comment on a previous test that my daughter should not erase her work so she could receive partial credit. Apparently this logic does not apply to factor of 10 problems. Any thoughts on this? I'd like feedback before I elevate this issue to the principal and/or superintendent of schools. The teacher feels she was within her rights to deduct the points since she instructed students to figure out the problem in their heads.