This cluster is about measurement using customary measurements. Customary measurement is positioned at this point in the curriculum sequence because students can leverage their knowledge of linear models with fractions, part of the previous cluster, to measure length to the nearest ¼ and ½ inch. This cluster is not about measuring using non-standard units that students experienced in grades K and 1. However, it is worthwhile to begin the unit with reminding students of the rationale
and need for standard units. (See About this Cluster and the Unpacking Document below for more details on this cluster.)
