Math--Chapter 4

Chapter 4: Use Addition and Subtraction

Lesson 1: Expressions. Objective: To write and evaluate addition and subtraction expressions.

Lesson 2: Addition Properties. Objective: To identify and use the properties of addition.

Lesson 3: Equations. Objective: To write and solve addition and subtraction equations using mental math. 

Lesson 4: Patterns: Find a rule. Objective: To find a rule and show the rule by writing an equation with variables.

Lesson 5: Balance Equations. Objective: To keep an equation equal by adding the same amount to both sides.

Lesson 6: Problem Solving Strategy: Act it out. Objective: To solve problems by using the strategy act it out.


Vocabulary:  expression, variable, Commutative Property, Associative Property,  parentheses, Identity Property, equation

expression:      a mathematical phrase that uses numbers and operation signs

variable:         a letter or symbol that can stand for any unknown letter

Commutative Property:  changing the order of the addends does not change the sum

Associative Property: changing how the addends are grouped does no change the sum

parentheses:  symbols used to sho what operations in an expression should be done first

Identity Property:  the sum of any number and zero is that number

equation:  a number sentence that states two amounts are equal


Rounding Help:

Rounding Rap

Mark the place. Look to the right. 4 or less are out of sight. 5 and up will buy one more before they too are out the door. In those empty right-hand spaces, zeros keep the proper places.

Estimating and rounding:

Rounding Whole Numbers:

 Our textbook website:


Some good practice websites: