This document defines key vocabulary terms related to variables, expressions, equations, and inequalities. It then provides examples of assigning variables to word problems and writing equations to represent relationships between variables. Key terms defined include variable, expression, equation, term. Examples shown include writing equations to represent relationships between a truck and car's weight, gallons and quarts, and the masses of Jupiter and Earth. Further examples demonstrate writing equations from word problems involving tapes and cost, hours and pay, gallons and miles, and pizzas eaten and left.

1. Identify and assign variables 06/04/09 PH 01-02 Bitsy Griffin

2. Vocabulary Variable A number represented by a letter. Number can change. Expression Mathematical phrase Incomplete sentence Variable Expression A mathematical phrase that contains at least one variable. 06/04/09 PH 1-2 Bitsy Griffin

3. Vocabulary Equations & Inequalities Complete mathematical sentences. Term (Terms) # Variable Product/quotient of a number Product/quotient of a number & variable Separated by a + or a - 06/04/09 PH 1-2 Bitsy Griffin

4. Term Examples 06/04/09 PH 1-2 Bitsy Griffin

5. # of Terms? 06/04/09 PH 1-2 Bitsy Griffin

6. Problem 1 The weight of the truck is two times the weight of the car. Assign the Variables: Truck Car Is Equation 06/04/09 PH 1-2 Bitsy Griffin > T > C > = > 2C=T OR T=2C

7. Problem 2 Four quarts are equal to one gallon. Assign the variables: Quarts Gallons Equation 06/04/09 PH 1-2 Bitsy Griffin > Q > G > 4Q=G OR G=4Q

8. Problem 3 The mass of Jupiter is 317.8 times the mass of Earth. Assign the variables Write the equation > J=317.8 E 06/04/09 PH 1-2 Bitsy Griffin

9. Write Equations 1 Tapes= Cost= Equation = 06/04/09 PH 1-2 Bitsy Griffin T C C=7.50T Tapes Cost 1 7.50 2 15.00 3 22.50 4 30.00

10. Write Equations 2 Hours= Pay= Equation = 06/04/09 PH 1-2 Bitsy Griffin H P P=7H Hours Pay 4 28.00 6 42.00 8 56.00 10 70.00

11. Write Equations 3 Gallons= Miles= Equation = M=25G This is an odd equation. We usually think in miles per gallon. 06/04/09 PH 1-2 Bitsy Griffin Gallons Miles 3 75 5 125 7 175 9 225

12. Write Equations 4 Pizzas Eaten= Pizzas Left = Equation = 06/04/09 PH 1-2 Bitsy Griffin PE PL PL=25 - PE This one wasn’t so easy! I had to notice that it was subtraction! Pizzas Eaten Pizzas Left 0 25 6 19 9 16 18 7

13. Review Variable Expression Equation Variable Expression Term Inequality 06/04/09 PH 1-2 Bitsy Griffin