Mrs. 0 also used drinking straws in a related activity, to represent place value and regrouping, Every day a "student helper" is invited to help lead the calendar activity by adding another straw to the total that represent the elapsed days in the school year. The straws accumulate until there are ten, and then are bundled with a rubber band. One notion behind this activity is that students will gain some concrete basis for understanding how numbers are grouped in a base ten system. Another is that they can begin to apprehend, first physically and then intellectually, how number groups can be composed and decomposed.