1. 10-7 6 th grade math Formulas and Variables

2. Objective To select and use formulas to solve algebraic problems. Why? To know solve formulas is a very important skill to help you in your further math and science careers. You will need to memorize several formulas in your life.

3. California State Standards AF 1.0: Solve simple linear equations … and interpret the results. NS 1.4 : Calculate given percentages of quantities …

4. Vocabulary Formula – A rule showing relationships among quantities. – An equation that expresses a rule. – Formulas usually contain variables. Use the rules in solving equations to isolate the variable. Distance formula » d = r x t » r = d/t or t = d/r

5. Important formulas Distance formula d = r x t Area of rectangle A = l x w Circumference C = Π x d or C = Π x 2 x r Winning percentage P = w (w = win, l = loss) w + l Pythagorean Theorem (for a right triangle) c ² = a² + b² Temperature formulas F = 9/5C + 32

6. How to Solve Formulas and Variables 1)Read for the known information 2)Write the correct formula 3) Substitute known information into formula. 4) Solve the formula. Remember the rules for solving equations. How long will it take to travel 145 mi at 58 mph? Formula: d = rt 145 = 58 x t t = 145 ÷ 58 t = 2.5 It will take 2 ½ hours

7. Try It! Use the formula: d = rt 1)d = 330 mi, r = 55 mph 2)d = 102 km, t = 1.2 hr Formula: f = $0.25 + $0.05d 3)d = 10 days 4)f = $1.30 1)330 = 55t t = 330 ÷ 55 t = 6 hr 2) 102 = 1.2r t = 102 ÷ 1.2 t = 85 km per hr or 85 km/h 3) f = 0.25 + 0.05(10) f = 0.25 + 0.50 f = $0.75 4) 1.3 = 0.25 + 0.05d 0.05d = 1.3 – 0.25 0.05d = 1.05 d = 1.05 ÷ 0.05 d = 21 days

8. Objective Review To select and use formulas to solve algebraic problems. Why? You now know solve formulas is a very important skill to help you in your further math and science careers. You will need to memorize several formulas in your life. You can use formulas to solve a problem by substituting in known values and solving for the unknown values.

9. Independent Practice Complete problems 5-8 Copy original problem first. Show all work! If time, complete Mixed Review: 9-13 If still more time, work on Accelerated Math.