## MATH - SCIENCE INTEGRATION

### Solving One Step Subtraction Problems

 In science, when you are using the formula for acceleration ( acceleration = (final velocity – initial velocity) / time ) 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

• Fractions using Calculator
 With the OGT calculator you will use the fraction key  to perfrom operations with fractions, when you want a fractional answer.  It is in the third row and the fifth column.  This will allow you to input fractions, both proper and improper, and mixed numbers.  Your solution will be a proper fraction or mixed number but you can also change from a mixed number to an improper fraction. The OGT calculator will also reduce all fractions in your final answer so you do not have to worry about it.

• Proper Fraction Calculations
 To input a proper fraction you input the numerator then the fraction key  then the denominator. Example :  4/9 Key strokes: Display:  4  9

• Mixed Numbers Calculations
 To input a mixed number you input the integer then the fraction key ,the numerator then the fraction key , and then the denominator. Example: 5 19/21 Keystrokes: Display:  5_19  21

• Improper Fractions Calculations
 You input an improper fraction the same way you do a proper fraction.  To input an improper fraction you input the numerator then the fraction key  then the denominator.  The calculator will turn it to a mixed number. Example:  11/6 Keystrokes: Display:  11  6 Hit any operation key and the calculator will convert the improper fraction to a mixed number. Display:  1_5  6

• Converting with Calculator
 To convert between mixed numbers and improper fractions you will use the inverse key   which is the second key in the first row, and the fraction key  .

• Improper Fraction to Mixed Number Calculations
 Change 8/5 to a mixed number. Key strokes: Display:  1_3  5 Mixed Number: 1  3/5 To convert back to an improper fraction do not clear the display. Keystrokes: Display:  8  5

• Mixed number to Improper Fraction Calculations
 Convert 13 9/11 to an improper fraction. Key Strokes: Display:  152  11 Improper Fraction:  152/11 To convert back to a mixed number do not clear the display. Key strokes: Display:  13_ 9 11

• Fraction to Decimal Calculations
 If you need a decimal answer from a fraction, remember all fractions are division problems, so input it as a division problem. Example:  Change 5/6 to a decimal Keystrokes: Display:  0.833333333 Read the directions from the problem to determine how many places you need after the decimal point.

• Addition using Calculator
 To add use the   which is in the seventh row and the fourth column.

• Integer Calculations
 -16 + 142 = Keystrokes: Display:  126

• Decimal Calculations
 4.9 + 17.83 = Keystrokes: Display:  22.73

• Fraction Calculations
 -7 9/17 + 14/23 = Keystrokes: Display:  8_54  391 Mixed Number:  8 54/391 To convert to an improper fraction, do not clear the display. Keystokes: Display:  3182  391 Improper Fraction:  3182/391

• Subtraction using Calculator
 To subtract use the   which is in the seventh row and the fifth column. Warning: Do not use the  for subtraction.

• Integer Calculations
 -2 - 76 = Keystrokes: Display:  -78

• Decimal Calculations
 45.36 - (-24.7) = Keystrokes: Display:  70.06

• Fraction Calculations
 - 4/9 - 8/11 = Keystrokes: Display:  -1_17  99 Mixed Number:   -1 17/99 To convert to an improper fraction, do not clear the display. Keystokes: Display:  -116  99 Improper Fraction:  -116/99

• ### Subtraction

 x - a = b Addition and subtraction problems are the same because you can change subtraction to addition then change the sign of the next number to the right to the opposite.

• Positive Integer Example
 x - 19 = 10 can be rewritten as x + (-19) = 10 Solve:  Add 19 to both sides of the equation x + (-19) + 19 = 10 + 19 Solution:  -19 + 19 = 0 so just x remains on the right hand side of the = 10 + 19 = 29 so 29 is on the left hand side of the = x = 29 Check:  Substitute 29 in for x in the original equation.  x -19 = 10 29 - 19 = 10 and 10 = 10 so 29  is the correct answer.

• Negative Integer Example
 x - (- 23) = - 56 can be rewitten as   x + 23 = - 56 Solve:  Add - 23  to both sides of the equation x + 23 + (- 23) = - 56 + (- 23) Solution:  23 + (- 23) = 0 so just x remains on the right hand side of the = - 56 + (- 23) = - 79 so - 79 is on the left hand side of the = x = - 79 Check:  Substitute - 79 in for x in the original equation. x - (- 23) = - 56 - 79 - (- 23) = -56 and -56 = - 56 so - 79  is the correct answer.

• Practice Exercises
 Exercise 1:  x - 15 = 89 Exercise 2:  x - (-7.63) = -92.56 Exercise 3:  x - 6/11 = 4/15 Hit next to check your answers.