Addition and Subtraction Strategies Unit of Study: Building Fluency with Addition and Subtaction Global Concept Guide: 1 of 2

Content Development  It is no accident that the standard says “know from memory” rather than “memorize”.  The standards are NOT dictating timed tests.

Day 1  Model for students how to use an open number line to add and subtract more fluently.  Then pose scenarios that model addition and subtraction sentences on an open number line to help students think flexibly.

Day 2  The purpose of this day is for students to understand the inverse relationship between addition and subtraction to help them build their fact fluency.  In the lesson ideas section of the GCG you can use the Fact Family Houses link as a tool to use with students.

Day 3/4  Understanding place value is a fundamental skill for students to be proficient at if they are to understand addition and subtraction as well as be fluent with their facts.  Use a lot of base ten models on this day to represent addition and subtraction scenarios with regrouping.  Example: can be represented as and =40and + = = 56

Day 5  On this day the focus is on using a part-part-whole mat to determine what the question is asking and assist students in thinking through the problem.  Use the part-part-whole questions under lesson ideas to guide your instruction.

Enrich/Reteach/Intervention  Reteach-Pull small groups of students and give them more exposure to the strategies. Manipulatives should be used to reinforce these addition and subtraction strategies.  Pose problems for students and encourage them to use mental math to solve the math using the strategies that have been covered in this GCG.