Translating variable expressions
What is the area of a rectangle? Length times Width If the length is 3 meters and the width is 2 meters, what is the area? A = L x W A = 3 x 2 = 6 meters 2 A, L and W are the  variables .  It is any letter that represents an unknown number.
An  algebraic expression   contains: 1) one or more numbers or variables, and 2) one or more arithmetic operations. Examples: x - 3 3 • 2n
In expressions, there are many different ways to write multiplication. 1) ab 2) a • b 3) a(b)  or  (a)b 4) (a)(b) 5) a x b We are not going to use the multiplication symbol any more. Why?
Division, on the other hand, is written as: 1)  2) x ÷ 3
Throughout this year, you will hear many words that mean addition, subtraction, multiplication, and division.  Complete the table with as many as you know.
Here are some phrases you may have listed. The terms with * are ones that are often used.
Write an algebraic expression for 1)  m  increased by 5. m  + 5 2) 7 times the product of  x  and  t. 7 xt   or  7( x )( t )  or 7 •  x  •  t
3) 11 less than 4 times a number. 4 n  - 11 4)  two more than 6 times a number. 6 n  + 2 5)  the quotient of a number and 12.
Which of the following expressions represents  7 times a number decreased by 13?  7x + 13 7x - 13 13 - 7x 13 + 7x Answer Now
Which one of the following expressions represents 28 less than three times a number?  28 - 3x 3x - 28 28 + 3x 3x + 28 Answer Now
Write a verbal expression for:  1) 8 +  a . The ratio of  m  to  r Do you have a different way of writing these? The sum of 8 and  a 2)
Which of the following verbal expressions represents 2x + 9? 9 increased by twice a number a number increased by nine twice a number decreased by 9 9 less than twice a number Answer Now
Which of the following expressions represents the sum of 16 and five times a number? 5x - 16 16x + 5 16 + 5x 16 - 5x Answer Now
base and 3 is called the exponent   or  power . 10 3  means 10 • 10 • 10 10 3  = 1000 When looking at the expression 10 3 , 10 is called the
How is it said? 2 1 Two to the first power 2 2 Two to the second power or  two squared 2 3 Two to the third power or  two cubed 2n 7 Two times n to the seventh power
Which of the following verbal expressions represents x 2  + 2x? the sum of a number squared and twice a number the sum of a number and twice the number twice a number less than the number squared the sum of a number and twice the number squared Answer Now
Which of the following expressions represents four less than the cube of a number? 4 – x 3 4 – 3x 3x – 4 x 3  – 4 Answer Now
Evaluate. 2 1 2 2 2 2 • 2 = 4 2 3 2 • 2 • 2 = 8 2n 7 We can’t evaluate because we don’t know what n equals to!!
Is 3 5  the same as 5 3 ? Evaluate each and find out! 3 5  = 3 • 3 • 3 • 3 • 3 =  243 5 3  = 5 • 5 • 5 =  125 243 ≠ 125  They are not the same!

Expressions powerpoint

  • 1.
  • 2.
    What is thearea of a rectangle? Length times Width If the length is 3 meters and the width is 2 meters, what is the area? A = L x W A = 3 x 2 = 6 meters 2 A, L and W are the variables . It is any letter that represents an unknown number.
  • 3.
    An algebraicexpression contains: 1) one or more numbers or variables, and 2) one or more arithmetic operations. Examples: x - 3 3 • 2n
  • 4.
    In expressions, thereare many different ways to write multiplication. 1) ab 2) a • b 3) a(b) or (a)b 4) (a)(b) 5) a x b We are not going to use the multiplication symbol any more. Why?
  • 5.
    Division, on theother hand, is written as: 1) 2) x ÷ 3
  • 6.
    Throughout this year,you will hear many words that mean addition, subtraction, multiplication, and division. Complete the table with as many as you know.
  • 7.
    Here are somephrases you may have listed. The terms with * are ones that are often used.
  • 8.
    Write an algebraicexpression for 1) m increased by 5. m + 5 2) 7 times the product of x and t. 7 xt or 7( x )( t ) or 7 • x • t
  • 9.
    3) 11 lessthan 4 times a number. 4 n - 11 4) two more than 6 times a number. 6 n + 2 5) the quotient of a number and 12.
  • 10.
    Which of thefollowing expressions represents 7 times a number decreased by 13? 7x + 13 7x - 13 13 - 7x 13 + 7x Answer Now
  • 11.
    Which one ofthe following expressions represents 28 less than three times a number? 28 - 3x 3x - 28 28 + 3x 3x + 28 Answer Now
  • 12.
    Write a verbalexpression for: 1) 8 + a . The ratio of m to r Do you have a different way of writing these? The sum of 8 and a 2)
  • 13.
    Which of thefollowing verbal expressions represents 2x + 9? 9 increased by twice a number a number increased by nine twice a number decreased by 9 9 less than twice a number Answer Now
  • 14.
    Which of thefollowing expressions represents the sum of 16 and five times a number? 5x - 16 16x + 5 16 + 5x 16 - 5x Answer Now
  • 15.
    base and 3is called the exponent or power . 10 3 means 10 • 10 • 10 10 3 = 1000 When looking at the expression 10 3 , 10 is called the
  • 16.
    How is itsaid? 2 1 Two to the first power 2 2 Two to the second power or two squared 2 3 Two to the third power or two cubed 2n 7 Two times n to the seventh power
  • 17.
    Which of thefollowing verbal expressions represents x 2 + 2x? the sum of a number squared and twice a number the sum of a number and twice the number twice a number less than the number squared the sum of a number and twice the number squared Answer Now
  • 18.
    Which of thefollowing expressions represents four less than the cube of a number? 4 – x 3 4 – 3x 3x – 4 x 3 – 4 Answer Now
  • 19.
    Evaluate. 2 12 2 2 2 • 2 = 4 2 3 2 • 2 • 2 = 8 2n 7 We can’t evaluate because we don’t know what n equals to!!
  • 20.
    Is 3 5 the same as 5 3 ? Evaluate each and find out! 3 5 = 3 • 3 • 3 • 3 • 3 = 243 5 3 = 5 • 5 • 5 = 125 243 ≠ 125 They are not the same!