Chapter 7.1 Writing Expressions and Equations Joke Time What did the ground say to the earthquake? You "crack" me up! Why did the Music teacher need a ladder? To reach the "HIGH" notes! What do elves learn in school? The elf abet!
Review key words for the different operations Drag word to correct operation ADDITION plus sum increased by more than MULTIPLICATION times product multiplied by decreased by less than minus difference quotient divided by SUBTRACTION DIVISION Word Phrases 9 more than a number the sum of 9 and a number a number plus 9 a number increased by 9 the total of x and 9 4 subtracted from a number a number minus 4 4 less than a number a number decreased by 4 the difference of h and 4 6 multiplied by g 6 times a number the product of g and 6 a number divided by 5 the quotient of t and 5 divide a number by 5 Algebraic Expression x + 9 h 4 6g t 5
Write an algebraic expression for each word phrase. Underline the key words in each sentence. Word Phrase five plus a number the product of five and a number eleven fewer than a number seventeen less than h the quotient of twenty and t Expression Word Phrase the sum of 2 and a number the quotient of a number and 2 the difference of 2 and a number 2 less than a number the product of 2 and a number
Seven less monkeys than Michael m 7 Five more cookies than Candace 5 + c The number of napkins divided by two people n 2 Nine times the number of kangaroos 9k Write a word phrase for each algebraic expression. Algebraic Expression Word Phrase q + 5 3 - t y / 5 12 x
Vocabulary Explain the difference between an expression and an equation. Click the clouds to check Expression written as a phrase does NOT have an equals sign can NOT be solved, you evaluate an expression by plugging in variable and simplifying the expression Equation is written as a sentence uses an equals sign to compare two values can be solved
Click on the equations. If you are correct, you'll see stars. 4y 2 = 7 2b + 1 7 y + 7y y 2 + y 4 12m 3 n 2 g 3 4 = 7 2x = 4 n 3 = 7 y 2 + y 4 z 2 = 5 4x 2 z 4 y + 2 (7) Key terms that suggest the equals sign... Examples: 8 is the sum of 3 and 5 $100 is as much as five $20 bills 32 is the same as the product of 2 and 16 67 is identical to 33 plus 34 a number x plus 10 is equal to 10 plus a number x Is Is as much as Is the same as Is identical to Is equal to Gives Equals a number plus 32 gives you 81 twenty-five equals the sum of twenty and five
Performance Task In each sentence below, circle the key words or phrases that indicate a mathematical operation and write the symbol for the operation above the words or phrases. Write an equation for each sentence. 8x = 33 a. A number multiplied by 8 gives 33. x 8 = 32 b. A number decreased by eight is equal to thirtytwo. x + y = 42 x 4 = 67 c. The sum of a number and a second number is forty two. a number increased by 7 is 11 n + 7 = 11 twice as many points as Bob would be 18 points 2b = 18 after dividing the money 5 ways, each person got $67 m 5 = 67 the price decreased by $4 is $29 p 4 = 29
Match the equation with the description. Algebraic Equation Description A number increased by nine is fifteen. Twice a number is eighteen. Four less than a number is twenty. A number divided by six is eight. y + 9 = 15 2n = 18 x 4 = 20 k 6 = 8 Match the equation with the correct sentence. Equation Phrase Seven dollars per hour for a total of $21 Jupiter has 18 moons. This is 2 times more moons than Neptune. 3m = 24 The distance between Little Rock and Benton is 24 miles. That is triple the distance between Little Rock and Maumelle. 24 = 3 = m 18 = 2n 7h = 21 h + 7 = 21 18(2) = n
Match the equations with the problems. Equation Problem A drop of 4 F per hour for several hours resulted in a total temperature change of 18 degrees. The total was $39 after a $5 tip was added. What was the original bill? A submarine dived 70 feet below its original depth. If the submarine's new depth is 550 feet, what was it's original depth? 4n = 18 5b = 39 n 4 = 18 b + 5 = 39 d 70 = 550 d 70 = 550