## IM Commentary

The purpose of this task is for students to measure lengths to the nearest eighth and quarter-inch and to record that information in a line plot. Both 4th graders and 5th graders use line plots to record measurement data given in fractions of a unit. Both 4.MD.4 and 5.MD.2 include adding and subtracting values given in the line plot. For 4th grade, this includes adding and subtracting fractions with like denominators. For 5th grade, this includes any operations with fractions through division of a whole numbers by a unit fraction (or vice versa; see 5.NF.A and 5.N.B).

The teacher should have a large assortment of round buttons for this activity and divide the students into partners or groups of three or four students. Each group should use 20 to 30 buttons for this activity.

This task does not explicitly ask operations-based questions, but it would be a strong task to introduce line plots with fractions. The teacher might consider prompting students to find the difference between the diameter of the biggest button and smallest button or to find the total length of the 5 biggest buttons placed right next to each other to address the other aspects of the standard.