1 / 16

Writing Algebraic Expressions

Writing Algebraic Expressions. Lesson 2-3. Word phrases can be written as algebraic expressions. Use the words to determine what operation you are using. Use a variable for the phrase “ a number. ”. Adding Phrases. Plus More than Sum Increased by. Subtracting Phrases. Minus Difference

gwyneth-young
Download Presentation

Writing Algebraic Expressions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Writing Algebraic Expressions Lesson 2-3

  2. Word phrases can be written as algebraic expressions. • Use the words to determine what operation you are using. • Use a variable for the phrase “a number.”

  3. Adding Phrases • Plus • More than • Sum • Increased by

  4. Subtracting Phrases • Minus • Difference • Subtracted from • Decreased by • Less than

  5. Multiplying Phrases • Times • Product of Dividing Phrases • Quotient • Divided by

  6. Example: 7 decreased by b “Decreased by” means subtract. 7 - b

  7. Example: The product of 19 and k “Product” means multiply. We show multiplication by placing the factor right next to the variable. 19k

  8. Less than, more than • Some word phrases contain the words “less than” or “more than.” • When you see those words, start with the second part of the phrase. Example: 23 less than m m - 23

  9. Example: 32 less than 5 times c The 32 is less than the 5 times c, which means we subtract 32 from the 5 times c. So, start with 5 times c. 5c - 32

  10. Tables • When you are given a table of values, determine how to get from the first column to the second column. • Describe that pattern with an algebraic expression.

  11. Example n ? 3 12 7 28 11 44

  12. Compare from left to right. • How do we get from 3 to 12? Add 9 or multiply by 4. • How do we get from 7 to 28? Multiply by 4. • If we multiply 11 by 4, we get 44. The pattern is to multiply our number, n, by 4. The algebraic expression to describe this is: 4n

  13. Describing Unknown Numbers • When you don’t know what a number is, let a variable stand for that number. • Use an algebraic expression to describe what you’re looking for.

  14. Example Write an algebraic expression to describe Jerry’s age. Use the following information: Jerry is 4 years younger than his brother Steve. First, we have to know how old Steve is. We do not have an age for Steve, so we will use a variable: Let s = Steve’s age. Now that we have determined Steve’s age (s), we can use it to determine Jerry’s age. Jerry is 4 years younger than Steve. s - 4

  15. If Steve is 22 years old, then how old is Jerry? s - 4 Jerry is 18 years old. 22 - 4 18

  16. Homework Time

More Related