Before You Begin this Unit… 

Unit at a Glance 
Unit 8 is the third unit in Grade 3 focused on addition and subtraction skills. By the end of this unit students should be able to demonstrate sound understanding of 3.NBT.2 – adding and subtracting within 1000. Your data from students’ performance in Units 1 and 3 will provide insight into your students’ specific needs. If students are still struggling with addition and subtraction combinations within 10, you may want to assess the combinations they know using the Hiding Assessment.
This unit builds upon the work of Units 1 and 3, as it extends students’ work with addition and subtraction with 3digit numbers. There continues to be a very intentional application of the base ten system as students will have opportunities to use expanded form and other place value strategies.
Please remember that the standard algorithm is not introduced in 3^{rd} grade as it can hinder place value understanding when introduced too early. 
Suggested Dates: Estimated Duration: 

Standards Addressed in the Unit  
3.OA.8 Solve twostep word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding. 