21st Century Lessons

Writing Algebraic Expressions

1

Warm Up-MatchingOBJECTIVE: SWBAT write an algebraic expression from a written expression.

Agenda

2

Choose the numerical expression that best matches each written expression.

93 a) the product of 9 and 3

b) 9 subtracted by 3

c) 9 divided by 3

d) the sum of 3 and 9

393939

1)

2)

3)

4)

dacb

Written Expression Numerical Expression

LANGUAGE OBJECTIVE: SWBAT discuss the difference between algebraic and written expressions.

Agenda:

1) Warm Up 2) Launch

3) Explore

4) Practice

5) Assessment

3

OBJECTIVE: SWBAT write an algebraic expression from a written expression.LANGUAGE OBJECTIVE: SWBAT discuss the difference between algebraic and written expressions.

Matching-Independent

Operations to Words-Groups

Mini Lesson-Whole Class

Matching Expression-Whole Class and Partners

Exit Slip-Independent and Partners

Agenda

Launch-Operations to Words

4

Agenda

Addition

Subtraction

Multiplication

Division

Directions: Put each word from the list into the operation’s box that it most likely expresses.

plus

sum

more thanin all

increased by

minus

less thandifference

subtract

decreased bytimes

of

product

each

multiplied

divided

perquotient

twice

ratio

less

factors

separate

PC Users

Launch- Mac User

5

Agenda

Addition

Subtraction

Multiplication

Division

Directions: Put each word from the list into the operation’s box that it most likely expresses.

plussum

more than

in allincreased by

minusless than

difference

subtractdecreased by

times

of

product

each multiplied

dividedper

quotient

twice

ratio

less

factors

separate

plus

sum

more thanin all

increased by

minus

less thandifference

subtract

decreased bytimes

of

product

each

multiplied

divided

perquotient

twice

ratio

less

factors

separate

Next Slide

Explore-Mini Lesson

7

Agenda

• The product of ten and seven.

• The product of ten and five.

Write the following as a

710 710

510 510• The product of ten and a number.Think…what can we use to represent a number when we don’t know the number?

VARIABLE

or

or

Click to reveal next part

numerical expression.

Explore- Mini Lesson

9

Agenda

The product of ten and a number.n10 n10 n10

Variable: a letter or symbol that represents an unknown quantity.

Now, for my next trick, I will introduce a new way to write multiplication.

A number written next to a variable means multiplication.

Write as a algebraic expression.

10

This new expression, 10n, is called an Algebraic Expression.

Why do mathematicians call them Algebraic Expressions?

• Algebraic Expression: an expression containing at least one variable.

• Numerical Expression: an expression containing one or more numbers and operations.

Explore- Mini Lesson

Vocabulary

Click to reveal next part

x n4 85 t

74 875

Agenda

11

• Written Expression: an expression written with words.

• Variable: any letter in the alphabet or symbol that represents an unknown quantity.

Explore- Mini Lesson

VocabularyThe sum seventeen and number

Three times the difference of nine and seven

n p h

Agenda

12

Write an algebraic expression for the problems below.a) The sum of ten and a number.

b) The quotient of a number and twelve.

c) Eleven decreased by five times a number.

x10

12t

n511

Practice- Whole Class

Important!!!!Identify theoperation(s) by underlining key words.

12

t

Agenda

13

Agenda

Name ________________ Date ___________

Class Work: Written Expressions vs. Algebraic Expressions

Directions: Match the written expressions in Column A with the algebraic expressions in Column B.

COLUMN A COLUMN B

The sum of a number and

ten

Ten divided by a number

Eight less than twice a

number

The product of ten and a number

increased by eight

The quotient of a number

and eight

Ten decreased by three times a number

The product of eight and a

number

10x 10x

x8 x10

x310 x210

810 x x8

82 x8

xEight increased by a number

Practice- Partners

14

Agenda

Class Work: Written Expressions vs. Algebraic ExpressionsDirections: Match the written expressions in Column A with the algebraic expressions in Column B.

COLUMN A COLUMN B

10x 10x

x8 x10

x310 x210

810 x x8

82 x8

x

Practice- Summary

The product of ten and a number

increased by eight

The sum of a number and ten

The quotient of a number and

eightEight less than

twice a number

Ten divided by a number

Ten decreased by three times

a number

Eight increased by a

number

The product of eight and a

number

A number decreased by

tenTen more than twice a number

Assessment- Exit Slip

15

Agenda

Directions: 1) Write your own algebraic expression using n, 3, 5. You must use at least 2 operations.

2) Translate your algebraic expression into a written expression.

3) Turn and Talk: Read your written expression to your partner. Have your partner write the algebraic expression. Switch roles.

3)