In that activity, students investigate the work people do and how they contribute to their households and to society. Activities of this sort are well-suited to collecting student writing. Asking children to reflect, for example, on their experience in mathematics class, produces interesting material for both teacher and parent. Portfolios for mathematics are being used by a number of elementary and middle grade teachers. Portfolios are a good vehicle to study students' growth and mathematical development over a period of time.
Portfolios also are a vehicle for involving students directly in self-assessment.
By asking children to select best pieces, for example, they must invest some thought into what represents good mathematical thinking. In order to use written work as part of the assessment process, teachers need to determine the areas they wish to evaluate, and then look for evidence within the writing about students' positions within those areas. There are a number of good resources that will help teachers explore more useful methods of assessing mathematical growth, and that discuss both the philosophical issues related to assessment, as well as the logistics of managing assessment.