Writing and Evaluating Expressions

Writing and Evaluating Expressions

Writing Expressions

• Identify your numbers and variables

• Identify your math words

• Write your expression

Multiple Choice

What is an algebraic expression?

• a letter or a symbol used to represent an unknown value

• an expression that contains one or more variables and may also contain an operation symbol such as + or -

• a specific number whose values does not change

Multiple Choice

Which of the following expressions contains a variable?

• 7+3

• 144÷12

• 7 + 15n

• 6(5)

Multiple Select

Identify only the numbers in the following question:

five minus twice a number

• five

• minus

• twice

• a number

Multiple Choice

What does the math word minus mean?

• addition

• subtraction

• multiplication

• division

Multiple Select

Which of these is a turn around phrase

• less than

• less

• quotient of

• product

Multiple Select

The product of m and 23 is shown in which expressions!!! CHECK ALL THAT APPLY!!!

• m⋅23

• 23+ m

• 23 x m (multiplication symbol)

• 23m

Open Ended

Which phrase describes this expression 16-y

Multiple Choice

What expression shows 22-12?

• the product of 22 and 12

• 22 fewer than 12

• 12 fewer than 22

• the quotient of 22 and 12

Multiple Choice

The quotient of z and 20 is shown in which expression?

• z+20

• z/20

• 20z

Open Ended

Sarah has some money in the bank, then she earned $12 more. Define a variable and write an expression for how much money she has in total.

Multiple Choice

James has $100. He decides to buy something from Walmart. Determine which expression can be used to calculate how much money he has left. Then, determine how much money he has left after he spends $25.

• The expression is 100+d. James will have $125 left.

• The expression is 100d. James will have $2,500 left.

• The expression is 100-d. James will have $75 left.

• The expression is 100/d. James will have $4 left.

Multiple Choice

Hillary rents out a building for $125. She charges guests $10 for each table that they use and $5 for each chair. Which expression can be used to calculate how much a guest will spend on an event? (Use t for the table and c for the chairs.)

• 125+10t+5c

• 125+15tc

• 125-10t-5c

• 125+(10t-5c)

Multiple Choice

Macy's mom gives her $100 for her birthday. She buys shirts that're $15 each and pairs of pants that're $25 each. Which expression can be used to calculate how much money she has left? (Use s for shirts and p for pants.)

• 100+15s+25p

• 100-15s+25p

• 100-(15s+25p)

• 100(15s+25p)

Multiple Choice

Perry has 17 fewer baseball cards than Pete.
If b represents the number of cards Pete has, write an expression for how many baseball cards Perry has.

• b + 17
• b -17
• 17 - b
• 17 + b

Multiple Choice

Jackson sells CDs for $7 each. Determine which expression can be used to calculate his sells. Then, determine how much money he'll make from selling 10 CDs. (Use c to represent the CDs.)

• The expression is 7c. He'll make $70 if he sells 10 CDs.

• The expression is 7c+10. He'll make $80 if he sells 10 CDs.

• The expression is 17c. He'll make $170 if he sells 10 CDs.

• The expression is 7+c. He'll make $17 if he sells 10 CDs.

Evaluate an Expression

• what is the value of 2x-1 if x = 2

• First, substitute 2 wherever you see x

• 2(2) - 1

• Solve using order of operations

• 4-1

• = 3

PRACTICE TIME!

Multiple Choice

What is the value of the expression, if p = 22?
p + 22

• 144
• 66
• 22
• 44

Multiple Choice

Evaluate 3x + 8   if x = 2

• 13
• 14
• 15
• 16

Multiple Choice

b² + 4
when b = 3

• 10
• 12
• 13
• 11

Multiple Choice

Evaluate when x = 8:
2x + x - 10

• 34
• 22
• 14
• 24

Evaluating expressions with multiple variables

• find the value of a + 2b -1 if a = 2 and b = 1

• Substitute the values for their variables

• a=2, 2 +2b - 1

• b = 1, 2+2(1)-1

• 2+2-1

• 4-1

• = 3

Multiple Choice

6a - 3d
when a = 1, d = 2

• 3
• 12
• 1
• 0

Multiple Choice

Evaluate the expression when b=3, c=10, and d=2.

 $\frac{bc}{d}$  

• 7.5

• 3.5

• 0.6

• 15

Multiple Choice

Evaluate the expression when m=4, n=3, and p=5.

p(m-n)

• 5

• 17

• 11

• 7

Multiple Choice

Evaluate the expression when x=7 and y=5.

xy

• 75

• 35

• 12

• 2

Multiple Choice

To find the perimeter of a rectangle, we use the formula P=2(L+w); where P stands for perimeter, L stands for length, and W stands for width. Find the perimeter of a rectangle that is 5 feet long and 9 feet wide.

• 14

• 28

• 45

• 8

Multiple Choice

To find the area of a triangle, we use the formula below. A stands for area, b stands for the base, and h stands for the height. Find the area of the triangle that has a base which measures 3 feet and a height of 6 feet.

 $A=\frac{bh}{2}$  

• 18 feet

• 9 feet

• 4.5 feet

• 1.5 feet 

Open Ended

What questions do you have about writing, reading, and evaluating algebraic expressions?

Exit Ticket

Answer the questions in the next three slides honestly

Poll

I can read algebraic expressions.

• Yes, I can say that.

• No, I'm not there yet.

Poll

I can write algebraic expressions.

• Yes, I can say that.

• No, I'm not there yet.

Poll

I can evaluate algebraic expressions.

• Yes, I can say that.

• No, I'm not there yet.