Algebraic Expressions

Algebraic Expressions - Remix

Objective

 SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Do I Know My Vocabulary Words?

Please answer the following questions.

 SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Multiple Choice

What is a variable?

• a term that includes a variable

• a term that is known without variables

• a letter that stands for an unknown number

Multiple Select

An algebraic expression is a mathematical phrase that includes:

• equal signs

• numbers

• words

• variables

• operation symbols

Let's Try

TURN ON YOUR THINKING CAP!!!!!

 SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Vocabulary

•  Variable – letter that represents one or more numbers.

   Ex. n

•  Coefficient – the number multiplied by the variable.

   Ex. 3n

• Algebraic Expression – mathematical phrase that can include numbers, variables, and operation symbols.

   Ex. 2x -4

• Equation – mathematical sentence that uses an equal sign.

   Ex. 4a + 2 = 10

• "Is" means = (equal)

• Exponents: times itself, square, cubed

   $x^2\ =\ x\ \times\ x$  

Key Words

Addition: sum, more, more than, plus, increased by, gain

Subtraction: difference, less, less than, minus, decreased by, loss

Multiplication: product, multiplied by, times, double, triple

Division: quotient, divided by, per, half, third, fourth, into groups

 SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Multiple Choice

Which operation does these words mean?

greater than, rise, ascend, positive, total, altogether

• Add

• Subtract

• Multiply

• Divide

Multiple Choice

Which operations does these words mean?

descend, difference, lower, takeaway, negative, decrease

• Add

• Subtract

• Multiply

• Divide

Let's look at some examples

Write "five plus three times itself" as an algebraic expression.

Step 1: What are the key words?

Step 2: What are the terms/numbers?

Step 3: Write out the expression. 

SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Answer

5 + 3² 

SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

ten less than a number

Step 1: What are the key words?

Step 2: What are the terms/variables?

Step 3: Write out the expression. 

SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Answer

x - 10 

SWBAT write algebraic expressions IOT interpret which operations to use in word problems and other mathematical concepts.

Multiple Choice

Which phrase represents "the sum of 11 and a number ?"

• 11 - x

• -11 + 1

• 11 + x

• =11 + x

Multiple Choice

Choose the right expression for "the difference of three and a number."

• 3x

• 3 - x

• x - 3

• ^3/x

Multiple Choice

Fourteen subtracted from a number is written as

• 14 - x

• 14 + x

• x - 14

• x/14

There are many ways to write a multiplication and division expression.

• For example, the word "product" tells us to use multiplication. So the phrase "the product of 8 and k" can be written as 8k, it means the same as 8 x k.

• Write an expression for "x divided by 9" can be written as   $\frac{x}{9}$  .  It means the same as x  $\div$  9.

Multiple Choice

the sum of 11 times a number s and 13

• 11 - 13s

• 11 + s + 13

• 11 + 13s

• 11s + 13

Multiple Choice

2 less than a number m divided by 8

• $\frac{m}{8}-\ 2$

• $m\ -8\ -\ 2$

• $m\ -\ 2\ \div8$

• $\frac{m}{2}\ -\ 8$

Open Ended

Lets Pull It All Together

Michelle has $142 in her saving account. Write an expression to determine the number of dollars left in her account after she withdraw d dollars.

Step 1: What do you know?

Step 2. What are the key words?

Step 3: What are the terms/variables?

Step 4: Write out the expression.

Answer

$142 - d

If Michelle withdraw $59 from her savings, how much money will she have in her account?

Step 1: What do you know?

Step 2: What are the key words?

Step 3: What are the terms/numbers?

Step 4: Write out the expression.

Answer

$142 - $59 = $83

Open Ended

We are Ready!!!!

John bought 45 stamps a post office. After he used x stamps, he had x less than 45 stamps remaining. Write an expression to represent.

b. How many stamps did John have left after using 33 stamps?

Open Ended

Describe the algebraic expression 2x + 5 in words.

Poll

Rate yourself on how you feel about evaluating expressions.

• Help me!!!

• I'm a genius!!!

• Maybe some more practice.