This document provides an introduction to expressions and equations in algebra. It defines expressions as statements that do not contain an equals sign, such as 2x - 4, while equations are statements that do contain an equals sign, such as 4n + 7 = 11. The lesson explains that students will practice writing verbal expressions and equations from algebraic forms, and vice versa. It provides examples and emphasizes using words like "more than", "less than", and "times" rather than symbols like "+" and "-".

1. Algebra I
Lesson 1-1
Expressions and Equations

2. 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

3. 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

4. What you will be doing today:
 Writing verbal
expressions and
equations from
algebraic forms
 Writing algebraic
expressions and
equations from verbal
forms

5. 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”

6. 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

7. 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”

8. Warning!!
Do not use the words
“plus” or “minus”
or “equals”
if at all possible !!

9. Your turn:
How would you write 4n + 3 as a verbal expression?
(you can discuss out loud with someone next to
you)

10. Now try this one:
Can you write the following in algebraic form?
“3 less than a number cubed is the same as
five”

11. 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

12. 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

14. Created by:
Kelly
Williams