1.1 Variables and Expressions/1.2 Order of Operations

Algebra 1A

1.1 - Variables and Expressions

1.2 - Order of Operations

Objectives

• To write algebraic expressions

• To use order of operations to simplify expressions

Vocabulary

• Quantity - Anything that can be measured or counted. Can be constant or variable

• Variable - a symbol (usually a letter) that represents the value of a variable quantity

• Algebraic expression - a mathematical phrase that includes one or more variables

• Numerical expression - a mathematical phrase involving numbers and operation symbols but no variables

• less than

• less

• subtracted from

• minus

• take away

​Words to look for in subtraction:

• more than

• plus

• increased by

• added to

​Words to look for in addition:

Addition/Subtraction

Examples

32 more than a number n

Examples

32 more than a number n

Examples

58 less a number

Examples

58 less a number

Quotient

Divided by

Share equally

Each

Split into

​Words to look for in Division

Times

Product

Twice

Total

Per

​Words to look for in Multiplication

Multiplication/Division

Examples

The product of 12 and a number

Examples

Examples

The quotient of a number and 5

 

Examples

Can we combine two operations?

3 more than twice a number

Can we combine two operations?

Multiple Select

How about going the other way?

Which of these word phrases can you use to represent the following algebraic expression?

$$x+8.1$$

Check all that apply.

• a number x increased by 8.1

• 8.1 less a number x

• 8.1 more than a number x

• The quotient of x and 8.1

Writing a rule for a pattern

Remember the In-N-Out Burger activity?

A Double-Double was a Cheeseburger plus $1.30.

A 3x3 was a Cheeseburger plus 2($1.30)

A 4x4 was a Cheeseburger plus 3($1.30)

Eventually we extended the pattern for any number of patties and used that to calculate the price of a 100x100.

You try:

Open Ended

The table shows how the height above the floor of a house of cards depends on the number of levels. 

What is the rule for height?  Give the rule in words.

Math Response

The table shows how the height above the floor of a house of cards depends on the number of levels. 

What is the rule for height?  Give the rule as a math expression. Use x as your variable.

Type answer here

Correct Answer: 3.5x+24

Deg^°

Rad