Clinical Calculation 5 th Edition

Clinical Calculation5th Edition Appendix B from the book – Pages 314 - 315 Appendix E from the book – Pages 319 - 321 Scientific Notation and Dilutions Significant Digits Graphs

Appendix B – Conversion between Celsius and Fahrenheit Temperatures • Although digital thermometers are replacing the old fashion thermometers these days, but as health care provider you should be able to convert between the Celsius and Fahrenheit and vise versa.

Comparing different thermometers The ones we are concern are Celsius ( C ) and Fahrenheit ( F ) http://asp.usatoday.com/weather/CityForecast.aspx?txtSearchCriteria=Oklahoma&sc=N http://weather.msn.com/

Converting Fahrenheit to Celsius 32F= _________________C

Converting Fahrenheit to Celsius 28F= ________________C

Converting Celsius to Fahrenheit 50 C = _________________ F

Appendix E – Twenty-four hour clock • Twenty-four hour clock is for documenting medication administration, specially with use of computerized MARs. • Rules: • To convert from traditional to 24-hours: • 1:00am and 12:00noon – delete the colon and proceed single digit number with a zero • Between 12noon and 12 midnight – add 12hours to the traditional time. • To convert from 24-fours clock to traditional: • Between 0100and 1200-replace colon and drop zero proceeding single digit numbers • Between 1300 and 2400-subtract 1200 (12 hours) and replace the colon.

24-Hour Clock Conversion Table12hr Time 24hr Time 12 am (midnight) 0000hrs 1 am 0100hrs 2 am 0200hrs3 am 0300hrs 4 am 0400hrs 5 am 0500hrs 6 am 0600hrs 7 am 0700hrs 8 am 0800hrs 9 am 0900hrs 10 am 1000hrs 11 am 1100hrs 12 pm (noon) 1200hrs 1 pm 1300hrs 2 pm 1400hrs 3 pm 1500hrs 4 pm 1600hrs 5 pm 1700hrs 6 pm 1800hrs 7 pm 1900hrs 8 pm 2000hrs 9 pm 2100hrs 10 pm 2200hrs 11 pm 2300hrs

Converting traditional clock to 24-hour clock • Examples: • 12 Midnight = 12:00 AM = 0000 = 2400 • 12:35 AM = 0035 • 11:20 AM = 1120 • 12:00PM = 12:00 Noon = 1200 • 12:30 PM = 1230 • 4:45 PM = 1645 • 11:50 PM = 2350 Midnight and Noon "12 AM" and "12 PM" can cause confusion, so we prefer "12 Midnight" and "12 Noon".

Converting 24 Hour Clock to AM/PM traditional • Examples: • 0010 = 12:10 AM • 0040 = 12:40 AM • 0115 = 1:15 AM • 1125 = 11:25 AM • 1210 = 12:10 PM • 1255 = 12:55 PM • 1455 = 2:55 PM • 2330 = 11:30 PM

Scientific Notation Scientists have developed a shorter method to express very large numbers. This method is called scientific notation. Scientific Notation is based on powers of the base number 10. The number 123,000,000,000 in scientific notation is written as : The first number 1.23 is called the coefficient. It must be greater than or equal to 1 and less than 10. The second number is called the base . It must always be 10 in scientific notation. The base number 10 is always written in exponent form. In the number 1.23 x 1011 the number 11 is referred to as the exponent or power of ten.

To write a number in scientific notation: • To write 123,000,000,000 in scientific notation: • Put the decimal after the first non-zero digit and drop the zeroes. • 1.23 • In the number 123,000,000,000 The coefficient will be 1.23 • To find the exponent count the number of places from the decimal to the end of the number. 1011 • In 123,000,000,000 there are 11 places. Therefore we write 123,000,000,000 as: 1.23 X 1011 • Exponents are often expressed using other notations. The number 123,000,000,000 can also be written as: • 1.23 E+11 or as • 1.23 X 10^11

Scientific Notation • For small numbers we use a similar approach. Numbers less smaller than 1 will have a negative exponent. A millionth of a second (0.000001 sec) is: • Put the decimal after the first non-zero digit and drop the zeroes • 1.0 (in this problem zero after decimal is place holder) • To find the exponent count the number of places from the decimal to the end of the number • 0.000001 has 6 places • 0.000001 in scientific notation is written as: • Exponents are often expressed using other notations. The number 0.000001 can also be written as: • 1.0 E-6 or as • 1.0^-6

Fun • Do you know this number, 300,000,000 m/sec.? • It's the Speed of light ! • Do you recognize this number, 0.000 000 000 753 kg. ? • This is the mass of a dust particle!

Now it is your turn. Express the following numbers in their equivalent scientific notational form: • 123,876.3 • 1,236,840. • 4.22 • 0.000000000000211 • 0.000238 • 9.10

Now it is your turn. Express the following numbers in their equivalent standard notational form: • 566.3 • 123,000. • 70,020,000 • 0.918 • 7.18 • 80,000

Dilutions • Understanding how to make dilutions is an essential skill for any scientist. This skill is used, for example, in making solutions, diluting bacteria, diluting antibodies, etc. It is important to understand the following: - how to do the calculations to set up the dilution - how to do the dilution optimally - how to calculate the final dilution

Volume to volume dilutions describes the ratio of the solute to the final volume of the diluted solution. • To make a 1:10 dilution of a solution, • you would mix one "part" of the solution with nine "parts" of solvent (probably water), for a total of ten "parts." • Therefore, 1:10 dilution means 1 part + 9 parts of water (or other diluent).

Serial dilutions • http://www.wellesley.edu/Biology/Concepts/Animations/dilution.mov

Serial dilutions - 1 mL 1 mL 1 mL 1 mL Original solution 9mL 9mL 9mL 9mL

Serial dilutions - 0.1 mL 1 mL 1 mL 1 mL Original solution 9.9 mL 9mL 9mL 9mL

Serial dilutions - 1 mL 1 mL 1 mL 1 mL Original solution 2mL 2 mL 2mL 2mL

Build Dilution ratio of 1:16 using 4 water blanks provided 3 mL 3 mL 3 mL 3 mL 3 mL 3 mL 3 mL 3 mL Original solution

Build Dilution ratio of 1:104 using 4 water blanks 1 mL 1 mL 1 mL 1 mL 9 mL 9 mL 9 mL 9 mL Original solution

Build Dilution ratio of 1:104 using 3 water blanks 0.1 mL 1 mL 1 mL 9.9 mL 9 mL 9 mL Original solution

Build Dilution ratio of 1:104 using 2 water blanks provided 0.1 mL 0.1 mL 9.9 mL 9.9 mL Original solution

Build Dilution ratio of 1:27 using water blanks provided 5 mL 5 mL 5 mL 10 mL 10 mL 10 mL Original solution

Serial dilutions - 1 mL 1 mL 1 mL 1 mL 1 mL # of bacteria found Original solution 9mL 9mL 9mL 9mL N EXPECTED NUMBER OF BACTERIA IN ORIGINAL SOLUTION

Serial dilutions - 0.1 mL 1 mL 1 mL 1 mL 5 mL # of bacteria found Original solution 9mL 9mL 9mL 9mL N EXPECTED NUMBER OF BACTERIA IN ORIGINAL SOLUTION

Serial dilutions - 0.1 mL 0.1 mL 0.1 mL 0.1 mL 2 mL # of bacteria found Original solution 9.9mL 9.9mL 9.9mL 9.9mL N EXPECTED NUMBER OF BACTERIA IN ORIGINAL SOLUTION

Significant Digits The number of significant digits in an answer to a calculation will depend on the number of significant digits in the given data When are Digits Significant? • Non-zero digits are always significant. Thus, • 22 has two significant digits, and • 22.3 has three significant digits. • With zeroes, the situation is more complicated: • Zeroes placed before other digits are not significant; • 0.046 has two significant digits. • Zeroes placed between other digits are always significant; • 4009 kg has four significant digits. • Zeroes placed after other digits but behind a decimal point are significant; • 7.90 has three significant digits. • Zeroes at the end of a number are significant only if it is followed by a decimal point or underlined emphasized on the precision: • 8300 has two significant digits • 8300. has four significant digits • 8300 has three significant digits

27.4 18.045 7600 7600. 7600 0.4003 4003 0.40030 40030 400.30 0.00403 40300 3 significant digits 5 significant digits 2 significant digits 4 significant digits 3 significant digits 4 significant digits 4 significant digits 5 significant digits 4 significant digits 5 significant digits 3 significant digits 3 significant digits Example: Identify number of significant digits

Operation using significant digits • Adding and subtracting – add and subtract as you normally do. • For the final solution the number of decimal places (not significant digits) in the answer should be the same as the least number of decimal places in any of the numbers being added or subtracted. . Add the following problem 5.67 (two decimal places) 1.1 (one decimal place) 0.9378 (four decimal place) 7.7078 7.7 (one decimal place)

Example - How precise can the answers to the following be expressed to? • 17.142 + 2.0013 + 24.11 • 17.142 has 3 numbers after the decimal points • 2.0013 has 4 numbers after the decimal points • 24.11 has 2 numbers after the decimal points • The answer could have two positions to the right of the decimal since the least precise term, 24.11, has only two positions to the right.

Example: Add / Subtract Subtract: 17.034 – 4.57 12.464 Add: 10.003 173.1 4 + 8.00003 195.00303 Final answer is 12.46 Final solution is 195. Subtract: 76 – 5.839 70.161 Add: 18.123 3.1 4.76 + 1.00 26.983 Final answer is 70. Final solution is 27.0

Operation using significant digits • Multiplying and dividing – do the operation as you normally do. • For the final solution use the least significant digits between all the numbers involved. • For example: • 0.000170 X 100.40 • The product could be expressed with no more than three significant digits since 0.000170 has only three significant digits, and 100.40 has five. So according to the rule the product answer could only be expressed with three significant digits.

Example - Indicate the number of significant digits the answer to the following would have. (I don't want the actual answer but only the number of significant digits the answer should be expressed as having.) (20.04) ( 16.0) (4.0 X 102) (20.04) has 4 significant digits ( 16.0) has 3 significant digits (4.0 X 102) has 2 significant digits Final answer will have 2 significant digits

1. 37.76 + 3.907 + 226.4 = 2. 319.15 - 32.614 = 3. 104.630 + 27.08362 + 0.61 = 4. 125 - 0.23 + 4.109 = 5. 2.02 × 2.5 = 6. 600.0 / 5.2302 = 7. 0.0032 × 273 = 8. (5.5)3 = 9. 0.556 × (40 - 32.5) = 10. 45 × 3.00 = 1. 268.1 (4 significant) 2. 286.54 (5 significant) 3. 132.32 (5 significant) 4. 129 (3 significant) 5. 5.0 (2 significant) 6. 114.7 (4 significant) 7. 0.87 (2 significant) 8. 1.7 x 102=170 (2 significant) 9. 4 (1 significant) 10. 1.4 x 102 (2 significant) Sample problems on significant figures

Rounding or Precision significant digits • Rules for rounding off numbers • If the digit to be dropped is greater than 5, the last retained digit is increased by one. • For example, • 12.6 is rounded to 13. • If the digit to be dropped is less than 5, the last remaining digit is left as it is. • For example, • 12.4 is rounded to 12. • If the digit to be dropped is 5, and if any digit following it is not zero, the last remaining digit is increased by one. • For example, • 12.51 is rounded to 13. • If the digit to be dropped is 5 and is followed only by zeroes, the last remaining digit is increased by one if it is odd, but left as it is if even. For example, • 11.5 is rounded to 12, 12.5 is rounded to 12. This rule means that if the digit to be dropped is 5 followed only by zeroes, the result is always rounded to the even digit. The rationale is to avoid bias in rounding: half of the time we round up, half the time we round down.

Graphs – Plotting Points on the Graph – how? y x y 1 3 4 6 0 -1 -2 -4 2 7 3 6 -2 -3 5 -6 x Decide the scale and follow within that scale setting (1=1)

Graphs – Plotting Points on the Graph y x y 1 3 4 6 0 -1 -2 -4 2 1 3 4 -2 -3 5 -1 x Decide the scale and follow within that scale setting (2=1)

Graphs – Plotting Points on the Graph y x y 1 3 4 0 -1 1 7 10 -2 -5 x 1=1

Drawing Straight Line y x y 1 3 4 0 -1 1 7 10 -2 -5 x 1=1 Points written as ordered pair: (1, 1), (3, 7), (4, 10), (0, -2), (-1, -5)

Drawing Straight Line y = 2x - 3 x y 0 1 2 -1 -3 -1 1 -5 (2, 1) (1, -1) (0, -3) (-1, -5) 1=1

Clinical Calculation 5 th Edition