## MATH - SCIENCE INTEGRATION

### Solving One Step Multiplication Equations

 In science, when you are using the formulas for force (force = mass x acceleration)  or for momentum (momentum = mass x velocity)  you will solve these equations the same way you would in math class.

### Using the Calculator

 On the Ohio Graduation Test "OGT" you will be allowed to use the calculator provided for the test.  In this section you can review the basic operations with the calculator as well as how to input negative numbers and fractions.

• Negative Numbers Calculations
 To input a negative number you use the  key in the last row to the left of the  key. You input the number first then the  key. Warning: Do not use the subtraction key  for negative numbers.
 Example:  -75.93 Keystrokes: Display:  -75.93

• Multiplication using Calculator
 To multiply use the  key   which is in the sixth row and the fourth column.

• Integer Calculations
 -72 x (- 89) = Keystrokes: Display:  6408

• Decimal Calculations
 4.6 x 8.62 = Keystrokes: Display:  39.652

• Fraction Calculations
 9/5 x 15/18 = Keystrokes: Display:  1_1  2 Mixed Number:  1 1/2 To convert to an improper fraction, do not clear the display. Keystokes: Display:  3  2 Improper Fraction:  3/2

• Division using Calculator
 To divide use the  key   which is in the sixth row and the fifth column.

• Integer Calculations
 16   44 = Keystrokes: Display:  0.363636363 Decimal Form:  0.36 If you need your answer in fractional form you can use the   instead of the   key. Keystrokes: Display:  - 4  11 Fractional Form:  - 4/11

• Decimal Caculations
 34.01 16 = Keystrokes: Display:  2.125625 Make sure you read the directions of each problem carefully so you will know what decimal place to round your answer to.

• Fraction Calculations
 -15 5/9 = Keystrokes: Diplay:  27

### Multiplication

 ax = b To solve multiplication equations you have to divide both sides of the equation by the number you are multiplying the variable by.

• Positive Integer Example
 3x = 21 Solve: Divide both sides of the equation by 3 (not 3x just 3) 3x  =  21                3         3 Solution:  Since 3/3 is 1 you have 1x, which is written as just x, on the right handside of the =. And 21/3 = 7 you have 7 on the left hand side of the =. x = 7 Check: Substitute 7 in for x in the original equation 3x = 21 3(7) = 21 and 21 = 21 so 7 is the answer to the equation.

• Negative Decimal Example
 - 4.79 x = 8.21 Solve: Divide both sides of the equation by - 4.79                     (not - 4.79x just - 4.79) - 4.79 x  =  8.21                 - 4.79        - 4.79 Solution:  Since - 4.79/- 4.79 is 1 you have 1x,                           which is written as just x,                          on the right hand side of the =. And 8.21/- 4.79 = -1.713987474                          (round to 2 places after the decimal)                          so you have -1.71 on the left hand side of the =. x = -1.71 Check: Substitute -1.71 in for x in the original equation                          - 4.79 x = 8.21 - 4.79 (-1.71) = 8.21 and  8.19 = 8.21 so -1.71  is the answer to the equation. (Remember we had to round our solution to 2 decimal                 places so in the check so there is a slight rounding error.)

• Practice Exercises
 Exercise 1:  5x = 60 Exercise 2:  -2.6x = 17.8                          (Round answer to 2 places after the decimal.) Exercise 3:  -7x = 49.63                       (Round answer to 2 places after the decimal.) Exercise 4:  10x = 6                         (Leave your answer in reduced fractional form.) Hit next to check your answers.