Writing Expressions

What is an Algebraic Expression? An algebraic expression contains at least one variable and at least one operation. Examples: 2 + a 4x c- 5 𝑦 5

What is a Variable? A variable is a letter that stands for a number. **ANY letter can be used as a variable.** *The letter x is most often used. Example: a x y

What is a Term? A term is a number, a variable, or a product or quotient of numbers and variables. Example: 3 a 3a 3 𝑎

What is a Coefficient? A coefficient of a term is the number in front of the variable. Example: 3a (3 is the coefficient) 4b (4 is the coefficient) 7x (7 is the coefficient)

Parts of an Expression Work with your table group to complete chart in your notes.   Coefficients Variables Exponents 8c2 9x y8 12a2b3

Addition sum more than total plus increased by

Examples of Addition Expressions 17 more than x n more than 18 A number increased by 17 18 increased by a number The total of a number and 17 The total of 18 and a number x plus 17 18 plus n The sum of x and 17 The sum of 18 and n

17 more than x x + 17 n more than 18 18 + n

Click the correct match 1 Click the correct match 10 more than x 10 + x x + 10

Click the correct match 2 Click the correct match x plus 25 25 + x x + 25

Click the correct match 3 Click the correct match 50 increased by x 50 + x x + 50

Click the correct match 4 Click the correct match the total of 17 and a number n + 17 17 + n

Click the correct match 5 Click the correct match the sum of c and 7 7 + c c + 7

Subtraction difference less than less minus decreased by

Examples of Subtraction Expressions subtract 17 from a number subtract a number from 18 17 less than x n less than 18 a number minus 17 18 minus a number a number decreased by 17 18 decreased by a number the difference of x and 17 the difference of 18 and n x less 17 18 less n

x - 17 18 - n 17 less than x n less than 18 subtract a number from 18 subtract 17 from a number 18 - n n less than 18 subtract a number from 18

Choose the correct match 6 Choose the correct match Subtract c from 12 c - 12 12 - c

Choose the correct match 7 Choose the correct match 45 less than n n - 45 45 - n

Choose the correct match 8 Choose the correct match 10 decreased by r 10 - r r - 10

Choose the correct match 9 Choose the correct match the difference of 60 and p p - 60 60 - p

Choose the correct match 10 Choose the correct match 75 less x x - 75 75 - x

Helpful Tip: When adding or subtracting a number from the variable, put the number and variable in the order of the words UNLESS the phrase contains the word than, from, or added to. Then you move the number you are adding or subtracting to the end of the expression. Ex. 6 more than p = p + 6 5 added to p = p + 5 5 from r = r - 5

Multiplication product times twice

Multiplication Expressions To avoid confusion with the “x” (multiplication) symbol, there are other ways to show multiplication. We will place the coefficient in front of the variable with no symbol.

They should be written in side-by-side form with the number (coefficient) always in front of the variable. 3a 2t 1.5c 0.4f

50n Examples of Multiplication Expressions 50 multiplied by n 50 times a number The product of 50 and a number

Division quotient divide

Division Expressions They should be written with the fraction bar for division instead of the division symbol. 𝑦 8 3 𝑡

Examples of Division Expressions 7 𝑛 𝑡 5 A number divided by 5 7 divided by a number The quotient of 7 and n The quotient of t and 5 Divide a number by 5 Divide 7 by n

Choose the correct match 8 times a number 8 𝑐 8c

Choose the correct match The product of 12 and n 12 𝑛 12n

Choose the correct match twice the number 2 𝑐 2c

Choose the correct match The quotient of 60 and a number 60 𝑛 𝑛 60

Choose the correct match 50 divided by x 50 𝑥 𝑥 50

Choose the correct match divide y by 75 75 𝑦 𝑦 75

Write the expression y increased by 20 y + 20 Answer

Write the expression x less than 90 Answer 90 - x

Write the expression Twice a number Answer 2n

Write the expression 10 decreased by n Answer 10 - n

Write the expression 80 divided by p Answer 80 ÷ p

Write the expression x more than 12 12 + x Answer

Write the expression the product of 21 and m Answer 21m

Write the expression The quotient of x and 9 Answer x ÷ 9

Write the expression Subtract 15 from n Answer n - 15

Write the expression The difference of y and 40 Answer y - 40

Write the expression The sum of 25 and a number 25 + n Answer

the difference between a number and 30 A number divided by 14 EXIT TICKET Write an algebraic expression for each of the following: the difference between a number and 30 A number divided by 14 The quotient of 56 and y 18 more than x The product of 78 and n

Writing Algebraic Expressions from Word Problems 𝑡 5

Writing Algebraic Expressions Write each phrase as an algebraic expression. Eight dollars more than Ryan earned. Step 1: Define a variable (What is the unknown?) r = Ryan’s earnings Step 2: Substitute variable for what Ryan earned in original problem. (What are we doing to Ryan’s earnings?) r + 8

Frank is a marathon runner Frank is a marathon runner. Write an expression to show the number of miles Frank ran if he completed 7 marathons. Answer 7x

Rhonda is 5 inches shorter than Anna Rhonda is 5 inches shorter than Anna. Write an expression for Rhonda’s height. Answer h - 5

Hank bought 4 movie tickets Hank bought 4 movie tickets. Write an expression to show how much he paid for the tickets. Answer 4x

Dan had some horses and 2 stables Dan had some horses and 2 stables. Write an expression to show how many horses he put in each stable. Answer 𝑥 2

In the school cafeteria, there are 40 small tables and some large tables. Write an expression to find the total number of tables. Answer 40 + n

Jill paid a certain amount for the bike and $5. 00 for shipping Jill paid a certain amount for the bike and $5.00 for shipping. Write an expression to show the total cost she paid. Answer b + 5

At the store, Dana bought some shoes on sale At the store, Dana bought some shoes on sale. Then she used her coupon for $10.00 off. Write an expression to show what she paid. Answer n -10

Mrs. Brown bought 20 pencils. Her students used some pencils Mrs. Brown bought 20 pencils. Her students used some pencils. Write an expression to show how many pencils are left. Answer 20 - x

Karen has 125 shells. She places n in each box Karen has 125 shells. She places n in each box. Write an expression to show the amount of shells in each box. Answer 125 𝑛

Six years less than Tracey’s age EXIT TICKET Define a variable then write an algebraic expression that represents the following situation: Six years less than Tracey’s age Two less than one-third of the points that the Panthers scored

Six feet less than the width EXIT TICKET Define a variable then write an algebraic expression that represents the following situation: Six feet less than the width Four hours more per week than Theo studies