Chapter 3 Solving Common Fraction Equations Copyright 2015

Common Fraction Equations • Solved by dividing numerators by denominators: Copyright © 2015 Copyright

Calculator Solution of Equations • Most safely done by concentrating only on entries being

Answers to Fraction Equations • Can be expressed as whole numbers or to the

Two Options • Option 1 – Calculator use throughout • Option 2 – Initial

Which Option to Use • Use option desired or option required by instructor. Copyright

Option 1 • In continuous entries, multiply numerators and divide by denominators: = 0.

Option 2 • Divide numerator 2 and denominator 4 by 2: becomes • Use

$Decimal Fraction Equations • Most dosage errors occur with use of decimal fraction equations.$

$Simplify Before Calculating • As with whole numbers, simplify numbers in decimal fraction equations$

Safety Point • Take particular care with calculator entry of decimal numbers to include

Option 1 • Multiply numerators and divide by denominators: • Answer = 3. 5

Option 2 • Move decimal points one and two places: becomes Two numbers follow

Option 2 (cont’d) • Divide 3 and 12 by 3. • Divide 210 and

Option 2 (cont’d) • Divide 42 and 4 by 2: becomes • Use calculator

$Multiple Number Equations • Use same options previously practiced with common fraction equations and$

Example of Multiple Number Fractions: Option 1 • Multiply numerators and divide by denominators:

Example of Multiple Number Fractions: Option 2 • Eliminate 1000 from numerator and denominator:

Example of Multiple Number Fractions: Option 2 (cont’d) • Use calculator to divide remaining

Safety Point • Double-check all calculator entries, calculator answers, and manual calculations. Copyright ©

Slides: 20

Download presentation

Calculator Solution of Equations • Most safely done by concentrating only on entries being done. – Not numbers that register and change throughout calculation Multiply the numerators, 3 and 5, and then divide by the denominators, 4 then 6, in continuous entries. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -3

Answers to Fraction Equations • Can be expressed as whole numbers or to the tenth or hundredth. – Depends on calculation being done Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -4

Two Options • Option 1 – Calculator use throughout • Option 2 – Initial fraction reduction – Followed by calculator use for final division 1 2 Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -5

Option 2 • Divide numerator 2 and denominator 4 by 2: becomes • Use calculator to divide remaining numerator by remaining denominators. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -8

$Decimal Fraction Equations • Most dosage errors occur with use of decimal fraction equations.$

$Simplify Before Calculating • As with whole numbers, simplify numbers in decimal fraction equations$

Simplify Before Calculating • As with whole numbers, simplify numbers in decimal fraction equations by eliminating decimal points and reducing numbers as optional first step. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -10

Safety Point • Take particular care with calculator entry of decimal numbers to include decimal point. • Routinely double-check each entry and answer. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -11

Option 1 • Multiply numerators and divide by denominators: • Answer = 3. 5 (tenth) or 3. 5 (hundredth) Hundredth would normally be 3. 50, but with medications, you remove the unnecessary 0. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -12

Option 2 • Move decimal points one and two places: becomes Two numbers follow the decimal in 0. 15, so you have to move all decimals in this fraction two places to the right. Always use the number that has the most decimals after it as your guide. (continues) Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -13

Option 2 (cont’d) • Divide 42 and 4 by 2: becomes • Use calculator to divide remaining numerator by remaining denominators: • Answer = 3. 5 (tenth) or 3. 5 (hundredth) Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -15

$Multiple Number Equations • Use same options previously practiced with common fraction equations and$

Multiple Number Equations • Use same options previously practiced with common fraction equations and decimal fraction equations. • Reduction of numbers may be of particular benefit here because calculations of this type sometimes have numbers that cancel and/or reduce dramatically. Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -16

Example of Multiple Number Fractions: Option 2 • Eliminate 1000 from numerator and denominator: becomes • Divide 6 and 4 by 2: (continues) Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -18

Example of Multiple Number Fractions: Option 2 (cont’d) • Use calculator to divide remaining numerators by remaining denominator: • Answer = 90 Copyright © 2015 Copyright Cengage©Learning® 2015 Cengage Learning® 3 -19