Cluster 5: Using Models to Add and Subtract Decimals and Fractions

This cluster continues the natural progression from place value to decimal computation. Students use the same length and area models to add and subtract decimals within real world and word problem contexts, developing an understanding that the meaning of addition and subtraction do not change simply because the numbers are decimals and fractions rather than whole numbers. They continue to explore addition and subtraction as inverse operations. Students equivalent fractions to add and subtract fractions with unlike denominators. They connect area models, length models, and other drawings to equations and discuss which strategies are efficient in different contexts.  (See About this Cluster and the Unpacking Document below for more details on this cluster.)