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
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: http://www.basic-mathematics.com/rounding-whole-numbers.html
Our textbook website: www.harcourtschool.com
Some good practice websites: