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:

http://www.math.com/school/subject1/lessons/S1U1L3GL.html

Rounding Whole Numbers: http://www.basic-mathematics.com/rounding-whole-numbers.html

Our textbook website: www.harcourtschool.com

Some good practice websites:

http://www.gamequarium.com/placevalue.html

http://www.softschools.com/math/games/

www.multiplication.com

www.funbrain.com