Writing Expressions and Equations. Word Clues Often words and phrases suggest addition, subtraction,...

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Writing Expressions and Equations

Transcript of Writing Expressions and Equations. Word Clues Often words and phrases suggest addition, subtraction,...

Writing Expressionsand

Equations

Word Clues

• Often words and phrases suggest addition, subtraction, multiplication, and division. You just need to know those words!

• Take notes!! You are about to receive your clue words!

ADDITION CLUES

Plus

Sum

More than

Increased by

In all

SUBTRACTION CLUES

Minus

Difference

Less than

Less

Decreased by

MULTIPLICATION CLUES

Times

Produce

Multiplied

Twice

Each

DIVISION CLUES

Divided

Quotient

Per

Separate

Writing phrases as algebraic expressions

Five dollars less than Jennifer earned

Less than is a subtraction clueWhen less than is used, the 2nd item is

always written first. Jennifer is the 2nd item; we don’t know her

earnings, so use a variable.

Writing phrases as algebraic expressions

Five dollars less than Jennifer earned

Since less than is subtraction and the 2nd item goes first, the beginning of the expression would like this:

j -

Writing phrases as algebraic expressions

Five dollars less than Jennifer earned

Now write the rest of the expression to complete the phrase!

j - $5

Twice as many tomatoes as last year

What’s our clue word? TWICEDo we know how many tomatoes there were

last year? NOSo, what should be used for the tomatoes?

VARIABLE

Writing phrases as algebraic expressions

Twice as many tomatoes as last year

What does twice mean? TWO TIMES

When a coefficient and a variable are being multiplied, remember how to write them!!

SMASHED TOGETHER LIKE PB&J

Writing phrases as algebraic expressions

Twice as many tomatoes as last year

2t

Writing phrases as algebraic expressions

3 more runs than the Pirates scored

Word Clue: MOREVariable Clue: Pirates undefined

3 + p

Writing phrases as algebraic expressions

The ONLY difference between expressions and equations:

the word: IS

Writing phrases as algebraic equations

Five more than a number is 20.

Word Clue: MORE THANVariable Clue: NUMBER IS UNDEFINEDEquation Clue: IS

Writing phrases as algebraic equations

Five more than a number is 20.

Write it as you read it!!!

5 + n = 20

Writing phrases as algebraic equations

Three times Jack’s age equals 12.

Word Clue: TIMESVariable Clue: JACK’S AGE UNDEFINEDEquation Clue: EQUALS

Writing phrases as algebraic equations

Three times Jack’s age equals 12.

Write it as you read it!!

3j = 12

Writing phrases as algebraic equations

Ten less a number is 8

Word Clue: LESSVariable Clue: NUMBER IS UNDEFINEDEquation Clue: IS

Notice that it is only LESS, not less than. This means to write it as you read it!!

Writing phrases as algebraic equations

Ten less a number is 8

10 – n = 8

Writing phrases as algebraic equations

Seven less than a number is 6

Word Clue: LESSVariable Clue: NUMBER IS UNDEFINEDEquation Clue: IS

Notice that it is LESS THAN, not less. This means to write the 2nd item first!!

Writing phrases as algebraic equations

Seven less than a number is 6

n – 7 = 6

Writing phrases as algebraic equations

You try these!

1) Eight more than x2) The sum of a number and four is -93) Nine less than t4) Twice a number equals -105) A number less 4 is 12.6) Five years older than Luis.7) A number divided by -128) Twice as many oranges.9) A number less 6.10) -15 divided by some number.

Writing phrases as algebraic equations and expressions