In this unit, students will learn how to write and interpret numerical expressions. They will be able to create simple numerical expressions, as well as interpret numerical expressions without evaluating them. Students are likely to struggle with interpreting the meaning of an expression and using precision to correctly write and evaluate expressions.
Key Concepts:
 A numerical expression represents both a "recipe" for calculating and a statement about numerical values.
 The goal of writing numerical expressions is not always to compute an "answer".
 We can use grouping symbols to represent different mathematical situations; these sometimes change the value of expressions and sometimes do not.
Prior Knowledge Needed:
 Represent and solve problems involving multiplication and division; (Grade 3, Unit 12, 3.OA)
 Solve problems involving the four operations, and identify and explain patterns in arithmetic; (Grade 3, Unit 15, 3.OA)
 Use the four operations with whole numbers to solve problems; (Grade 4, Unit 8, 4.OA)
 Use the four operations with whole numbers to solve problems; (Grade 4, Unit 14, 4.OA)
 While additive (or absolute) comparisons show "n more than" or "n less than", multiplicative, or relative, comparisons show "n times as many" or "n times as large"; (Grade 5, Unit 7)
Units on the Horizon:
 Reason about and solve onevariable equations and inequalities; (G6, Unit 5, 6.EE)
 Use variables to represent numbers and write expressions when solving a realworld or mathematical problem; understand that a variable can represent an unknown number, or, depending on the purpose at hand, any number in a specified set; (G6, Unit 5, 6.EE)
Lessons

Lesson objective: Understand that an expression is a way to list out mathematical calculations, and has a specific order in which it must be evaluated. Students bring prior knowledge of multistep problem solving with all four operations from 4.OA.A.3, ...

Lesson objective: Write numerical expressions about reallife or mathematical situations. This lesson helps to build fluency with writing numerical expressions. Pictures of items are used here because they help students visualize the items and amounts d...

Lesson objective: Evaluate numerical expressions using the order of operations. This lesson helps to build the procedural skill of evaluating expressions. Tables are used here because they help students organize their thinking so evaluating is done one ...

Lesson objective: Apply understanding of how to create and evaluate numerical expressions to a reallife situation. This lesson provides an opportunity for students to apply their knowledge and understanding of creating and evaluating numerical expresio...

Lesson objective: Understand that many expressions can be interpreted without evaluating them. Students bring prior knowledge of multiplicative comparison from 4.OA.A.1, 4.OA.A.2, and 5.NF.B.5. This prior knowledge is extended to expressions as students...

Lesson objective: Interpret the meaning of expressions without evaluating them. This lesson helps to build fluency with intepreting expressions. Base ten blocks and tape diagrams are used here because they help students visualize the relationship betwee...

Lesson objective: Apply understanding of how to create and interpret expressions without evaluating them. This lesson provides an opportunity for students to apply their knowledge and understanding of creating and interpreting expressions to a reallife...

Lesson objective: Understand that grouping symbols sometimes change the value of an expression, but not always. Students bring prior knowledge of solving problems with the four operations from 4.OA.OA.3, 5.NBT.B.5, and 5.NBT.B.6. This prior knowledge is...

Lesson objective: Practice using parentheses to make an equation true. This lesson helps to build fluency with using grouping symbols like parentheses in an equation to make it true and correctly represent a reallife or mathematical situation. Tables a...

Lesson objective: Apply knowledge of how to create, interpret, and evaluate expressions with all four operations and parentheses in order to come up with a reallife situation for a numerical expression. This lesson provides an opportunity for students ...