Writing Equations

Writing Equations

​

By Katherine Booth

Today you will learn how to write equations.

***you will NOT be solving equations, just WRITING them!!***

​You will NOT be writing anything in your notebook today, but the following slides you will:

​

• Learn the difference between expressions and equations

• Practice writing equations

​Look at the image. Compare the similarities and differences between equations and expressions.

Discuss with a partner

​

What is the main difference you see?

Multiple Choice

What is the most important difference between an expression and an equation?

• they're spelled different

• an equal sign

• only equations have variables

• only expressions have variables

Multiple Choice

An equation is :

• a mathematical phrase that has an equal sign / una frase matemática que tiene un signo igual

• a mathematical phrase that DOES NOT has an equal sign / es una frase matemática que no tiene signo igual

Multiple Choice

An expression is:

• a mathematical phrase that has an equal sign / una frase matemática que tiene un signo igual

• a mathematical phrase that DOES NOT have an equal sign / es una frase matemática que no tiene signo igual

Multiple Choice

A variable is:

• an equal sign / un signo igual

• a letter used to represent an unknown number / una letra que se usa para representar un número desconocido.

• a mathematical phrase / una frase matemática

• I don't know / no sé

Before we write equations, lets refresh our memory on key words

Multiple Choice

More than in the phrase means you...

• subtract

• add

• multiply

• divide

Multiple Choice

Difference means to...

• add

• subtract

• multiply

• divide

Multiple Choice

Product means to...

• add

• subtract

• multiply

• divide

Multiple Choice

Quotient means to...

• add

• subtract

• multiply

• divide

Ready to practice?

​Take your TIME!!!! You have 5-15 minutes for each problem.

​

Work TOGETHER!!! ​

Multiple Choice

What do the following terms mean:
is
equal
the same as 

• +
• -
• =
• x

Multiple Choice

Write an equation models the following statement:
 17 less than h equals 42

• 17-h=42
• h-17=42
• h+17=42
• 17+h=42

Multiple Choice

Translate the statement into an equation:
Five less than a number is 6

• n - 5 = 6
• 5 - n = 6

Multiple Choice

Translate the sentence into an equation.
Seven subtracted from n is 18 

• n + 7 = 18
• 7 - n = 18
• n - 7 = 18
• n + 7 = 18n

Multiple Choice

twice a number is the same as 36

• x + 2 = 36

• x - 2 = 361

• 2x = 36

• x/2 = 36

Multiple Choice

x + 12 = 20

• 12 times a number is the same as 20.

• a number divided into 12 groups equals 20.

• The sum of a number and 12 equals 20.

• a number decreased by 12 is 20.

Multiple Choice

4 is the quotient of 16 and a number n.

• 4 = 16n

• 4 = 16/n

• 4 = 16 + n

• 4 = 16 - n

Multiple Choice

Your friend writes the word sentence as an equation. Is your friend correct?

• Yes

• No

Multiple Choice

A crew is picking up chairs in the gymnasium after an event. After clearing 217 chairs from the gym floor, 36 chairs still remain. Write an equation you can use to find the number of chairs placed on the gym floor for the event.

• 217n = 36

• n - 217 = 36

• n + 217 = 36

• n/217 = 36

Multiple Choice

Twice a number plus 6 times the number is -72

• 2 + 6x =- 72
• 2x + 6x = -72
• 2 + 6 = x
• 2y x 6y = 72

Multiple Choice

Eight less than 7 times a number is the same as 4 more than 3 times the number

• x + 3 = x
• 8 = x + 4 + 3
• 8 - 7n = 4 + 3n
• 7x - 8 = 3x + 4

Multiple Choice

What equation matches this situation?
John wants to buy an MP3 Player that costs $30.98.  How much change did he receive if he gives the cashier $40.

• 40 + c = 30.98
• 30.98 + c = 40
• c - 40 = 30.98
• c - 30.98 = 40

Multiple Choice

Pizzazz Publications is having some books printed. The printer charges $800 plus $5 per book. What equation could help me find how many books can be printed for $4,000?

• 800 + 5x = 4000
• 800x + 5 = 4000
• 4000 + 5x= 800
• 800 + 5 = 4000

Multiple Choice

The space club is having some posters printed. The printer charges $250 plus $2 per poster. How can I figure out how many posters I could print for $1,000?

• 250x + 2 = 1000
• 1000 + 2x = 250
• 250 - 2x = 1000
• 2x + 250 = 1000

Multiple Choice

Grandpa Gump is 63 years old. His age is 2 years less than 5 times the age of Billy Gump. How could I find out how old Billy is?

• x/5 - 2 = 63
• 5x - 2 = 63
• 2x - 5 = 63
• 5x + 2 = 63

Multiple Choice

Three desks and a bookcase together weigh 157 pounds. The bookcase weighs 34 pounds. Which equation could help me find out how much each desk weighs?

• 34 + 3 = 157
• 34x + 3 = 157
• 3x + 34 = 157
• x + 34 = 157

Multiple Choice

Oshgosh would like to buy a new pair of skates for $115. So far he has saved $40. If he earns $7.50 per hour, how could I find out how many hours he must work in order to buy the skates?

• 40 + 7.50x = 115
• 40x + 7.50 = 115
• 40 + 7.50 = 115
• 40 + 17.50x = 115

Multiple Choice

Jo is thinking of a number. Four less than 9 times the number is 176. How could I find Jo's number?

• 9x - 4 = 176
• 4 - 9x = 176
• 9x + 4 = 176
• 4x + 9 = 176

Multiple Choice

Mr. Piper's plumbing needed repairs. The plumber charged $98 for parts plus $45 per hour for labor. If the bill totaled $458, how could I find out the hours of labored required?

• 98x + 45 = 458
• 98 + 45x = 458
• 45 + 98 = 458
• 45x - 98 = 458

Multiple Choice

Ken is thinking of a number. Nine more than the product of 4 and the number is 73. What is the equation?

• 4 + 9x = 73
• 4x = 73
• 4x + 9 = 73
• 9x + 4 = 73

Multiple Choice

The 30 members of a choir are trying to raise $1500 to cover travel costs to a singing camp. They have already raised $600. Which equation would you solve to find the average amount each member can raise in order to meet the goal?

• 30x + 600 = 1500
• 30x - 600 = 1500
• x + 600 = 1500
• 30x = 1500