Algebra ILesson 1-1

Expressions and Equations

Expressions are:

General little statements that

DO NOT have an equals sign! • 2x – 4• 2m³ + 5m• Seven less than half a number squared• Twice the difference of a number and five

Equations are:

Any statement that DOES have

an equals sign (or equivalent):• 4n + 7 = 11• ½ b – 2 = 3• Twice a number increased by four is ten• The difference of a number and two is five

What you will be doing today: Writing verbal

expressions and equations from algebraic forms

Writing algebraic expressions and equations from verbal forms

What does THAT mean? It means you will take

an expression like 3x – 5, and write it as: “the difference of three times a number and five” or maybe “ five less than three times a number”

Or maybe……If you are given the verbal sentence, you will write it

as an algebra equation or expression:

“half of a number increased by three is twelve” would be written as : ½ x + 3 = 12

What will you need to know to be able to do this?

Words for addition, such as “more than” or “increased by”

Words for subtraction, such as “less than” or “decreased by”

Words for multiplying or dividing, such as “product of” or “quotient”

Words for powers of numbers, like “squared” or “cubed”

Words for where the equals sign goes, like ‘is” or “is equal to” or “is the same as”

Warning!!

Do not use the words “plus” or “minus” or “equals”

if at all possible !!

Your turn:How would you write 4n + 3 as a verbal expression?

(you can discuss out loud with someone next to you)

Now try this one:Can you write the following in algebraic form?

“3 less than a number cubed is the same as five”

Which ones are correct for 2m – 7:

Twice a number less than seven

Seven decreased by twice a number

Seven less than twice a number

Twice a number decreased by seven

3m² + 2 = 14 would be written: Two more than 3

times a number squared is fourteen

Three m’s squared plus two equals fourteen

Three times a number squared increased by two is the same as fourteen

Created by:

Kelly Williams