Upcoming SlideShare
×

# Fractions

2,152 views

Published on

• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

### Fractions

1. 1. Gray Morris Mosby items and derived items © 2010 by Mosby, Inc., an affiliate of Elsevier Inc.
2. 2. Unit One: Chapter 2 Mosby items and derived items © 2010 by Mosby, Inc., an affiliate of Elsevier Inc.
3. 3. <ul><li>After reviewing this chapter, you should be </li></ul><ul><li>able to: </li></ul><ul><ul><li>Compare the size of fractions </li></ul></ul><ul><ul><li>Add fractions </li></ul></ul><ul><ul><li>Subtract fractions </li></ul></ul><ul><ul><li>Divide fractions </li></ul></ul><ul><ul><li>Multiply fractions </li></ul></ul><ul><ul><li>Reduce fractions </li></ul></ul>
4. 4. <ul><li>Seen in </li></ul><ul><ul><li>medical record, client record, charting, and medical/nursing literature </li></ul></ul><ul><li>Used in calculation types </li></ul><ul><ul><li>Apothecary </li></ul></ul><ul><ul><li>Household </li></ul></ul>
5. 5. <ul><li>A fraction is part of a whole number </li></ul><ul><ul><li>½ is a whole divided into two parts </li></ul></ul><ul><li>Have a numerator & a denominator </li></ul><ul><ul><li>Figure 2-2 Diagram representing fractions of a whole. Five parts shaded out of the six parts represent: </li></ul></ul>
6. 6. <ul><li>Fractions may be used on drug labels in addition to metric equivalent to help clarify </li></ul><ul><li>and prevent errors </li></ul><ul><ul><li>Cohen, M. (2007). Medication Errors, 2 ed. </li></ul></ul><ul><li>2.5 mg (2½ mg) Coumadin on same label </li></ul>
7. 7. <ul><li>Proper </li></ul><ul><ul><li>Numerator is less than denominator; the fraction has a value of less than 1 </li></ul></ul><ul><ul><li>Examples: </li></ul></ul><ul><li>Improper </li></ul><ul><ul><li>Numerator is larger than, or equal, to denominator; the fraction has a value of 1 or greater than 1 </li></ul></ul><ul><ul><li>Examples: </li></ul></ul>
8. 8. <ul><li>An improper fraction can be changed to a mixed number or whole number by dividing the numerator by the denominator </li></ul>
9. 9. <ul><li>Mixed </li></ul><ul><ul><li>A whole number and a fraction; the value is greater than 1 </li></ul></ul><ul><ul><li>Example: </li></ul></ul><ul><li>Complex </li></ul><ul><ul><li>Numerator, denominator, or both, are fractions; the value may be less than, greater than, or equal to 1 </li></ul></ul><ul><ul><li>Example: </li></ul></ul>
10. 10. <ul><li>Whole numbers </li></ul><ul><ul><li>Have an expressed denominator of one (1) </li></ul></ul><ul><ul><li>Examples: </li></ul></ul>
11. 11. <ul><li>If the numerators are the same, the fraction with the smaller denominator has the larger value </li></ul><ul><ul><li>Example: </li></ul></ul><ul><li>If the denominators are the same, the fraction with the larger numerator has the larger value </li></ul><ul><ul><li>Example: </li></ul></ul>
12. 12. <ul><li>A mixed number can be changed to an improper fraction by multiplying the whole number by the denominator, adding the numerator, and placing the sum over the denominator </li></ul><ul><ul><li>Example: </li></ul></ul>
13. 13. <ul><li>The value of a number is unchanged when the numerator and denominator are multiplied or divided by same number </li></ul><ul><ul><li>Example: </li></ul></ul><ul><li>Change a fraction to lowest terms by dividing numerator and denominator by the largest whole number that will divide into both evenly </li></ul><ul><ul><li>Example: </li></ul></ul>
14. 14. <ul><li>LCD (lowest common denominator) is the smallest whole number that can be divided evenly by all the denominators in the problem </li></ul><ul><ul><li>Example: </li></ul></ul>
15. 15. <ul><li>Should always be reduced to lowest terms </li></ul><ul><li>Numerator and denominator are each divided by the largest number by which they are both evenly divisible </li></ul><ul><ul><li>Example: </li></ul></ul>
16. 16. <ul><li>With same denominator, add the numerators, then reduce to lowest terms </li></ul><ul><ul><li>Example: </li></ul></ul><ul><li>With different denominators, change fraction to equivalent denominators by using the LCD, then add numerators as described above </li></ul><ul><ul><li>Example: </li></ul></ul>
17. 17. <ul><li>The rules for subtraction are the same as those for addition </li></ul><ul><ul><li>If denominators are the same , perform subtraction with the numerators, obtain the value, place it over the denominator, and reduce to lowest terms </li></ul></ul><ul><ul><li>If denominators are different , find the lowest common denominator (LCD), change to equivalent fractions, subtract the numerators, and place that value over the common denominator. Reduce if necessary. </li></ul></ul>
18. 18. <ul><li>Multiply numerators together </li></ul><ul><li>Multiply denominators together </li></ul><ul><li>Reduce if necessary </li></ul><ul><ul><li>Note: Fractions can be reduced to lowest terms before multiplication </li></ul></ul><ul><ul><li>Express whole numbers as fractions with a denominator of 1 to visually aid in multiplication </li></ul></ul>
19. 19. <ul><li>Invert the second number (turn it upside down) and then multiply. Reduce if necessary. </li></ul><ul><ul><li>Note: Change mixed numbers to improper fractions before performing division steps </li></ul></ul>
20. 20. <ul><li>When dividing mixed fractions, change the problem visually so that division steps are easily seen </li></ul>