Cluster 5: Operating with Place Value
In this cluster, students operate with place value, building on students understanding of place value with numbers 11-19, and extending understanding to addition and subtraction within 100. Students will build on this place value understanding to add and subtract. They will continue to build understanding of equality and equations by introducing symbols and solving for unknowns in word problems. Students will mentally find 10 more or 10 less than a given two-digit number by explaining their reasoning in terms of place value understanding, not counting. (See About this Cluster and the Unpacking Document below for more details on this cluster.)
