1. NAB 630 Medical Calculations Aug 28, 2008

2. Scientific Notation (SN)  a way of expressing very small numbers such that the zeroes are omitted  the numbers are much more manageable to work with  done by moving the decimal point to the right of the first non zero number followed by x10 to the power of how many places the decimal point was moved  from the left the sign of the power is negative and from the right no sign is given; understood that it is positive.

3. Express 0.0021 In SN  Move decimal point to after the 2  Moved it three places from the left so 10 -3  Express in SN: 2.1 x 10 -3

4. Express 10400000 In SN  Move decimal point to right after the 1  Moved it 7 places from the right so 10 7  Express in SN: 1.0 x 10 7

5. Express 3449999999999 In SN  Move decimal point to right after the 3  Moved it 12 places from the right so 10 12  Round off number to 3.45  Express in SN: 3.45 x 10 12

6.  also called significant figures  those digits that carry meaning contributing to its accuracy  gives the reader the extent of the level of confidence in a certain value Significant Digits

7.  All non-zero digits are significant 1234 has four significant digits 1234.56 has six significant digits 12304 has five significant digits 123.04 has five significant digits  Zeros that are leading zeros because they appear first in a number are not significant 0.0009 has one significant digit 0.09102 has four significant digits  Trailing zeros in a number that contains a decimal point are significant. 9.1000 has five significant digits 22.0080000 has nine significant digits Rules

8. Trailing Zeroes Without DP  The last significant digit is marked by a bar placed over the digit and all digits following that are not significant. Each of the following in bold has a bar over it I.10000 has three significant digits (accurate to the hundred) II.12300000 has eight significant digits (accurate to the one)

9.  The number of significant figures can be designated by the abbreviation, s.f. I.2000 (2 s.f.) means there are only two significant figures II.2000 (3 s.f.) means there are three significant figures. A decimal point may be placed after the number; for example "100." indicates specifically that three significant figures are meant. Trailing Zeroes Without DP

10.  The last significant figure can also be marked by an underline 2000 has four significant digits 2000 has two significant digits  The number of significant figures can be designated by the abbreviation, s.f. 2000 (2 s.f.) means there are only two significant figures 2000 (3 s.f.) means there are three significant figures.

11. Unit Conversions  Converting from English to Metric or Metric to English  Can be done as long as you know the conversion factor (direct equivalence) or factors (indirect equivalences)  In the conversion factor the unit to be changed (the original) is always on the bottom  Use the following formula: original unit X conversion factor(s) = New unit

12. English And Metric Units LENGTHVOLUMEMASS 1 inch=2.54 cm1ft 3 =28.32l1lb=453.59g 39.37 inch= 1m1.05 qt = 1l1 oz = 28.35 g 1 mile= 1.61 km1 gal = 3.7853l

13. Per Liter micromillicentidecikilo 1,000,0001000100100.001

14. Per Gram micromillicentidecikilo 1,000,0001000100100.001

15. Liter Per micromillicentidecikilo 1x10 -6 1x10 -3 1x10 -2 1x10 -1 1x10 3

16. Gram Per micromillicentidecikilo 1x10 -6 1x10 -3 1x10 -2 1x10 -1 1x10 3

17. Conversion Problems Problem 1: 20g = ? lbs Conversion factor: 1lb=454g Formula: Original unit X conversion factor = New unit Calculation: 20g x 1lb/454g =0.04 lbs Problem 2: 100 yards= ? km Conversion factor: 39.37 inch=1 meter Formula: Original unit X conversion factor = New unit Calc: 100 yds x 36 inches/1yd x 1 m/39.37 inches = 91.44 m

18. Problem 3: 20 liters = ?deciliters Conversion factor: 1l=10 dl Formula: Original unit X conversion factor = New unit Calculation: 20 l x 10 dl/1l = 200 dl Problem 4: 1 year = ?seconds Conversion factors: 1 yr=52 wks; 1wk=7days; 1day=24 hrs; 1hr/60 min; 1m/60s Formula: Original unit X conversion factor = New unit Calc: 1yr x (52 wks/yr) x (7days/1wk) x (24hr/day) x (60m/hr) x (60s/m) =

19. Dilution Calculations C 1 V 1 = C 2 V 2 Problem 1: How much of a 2M NaOH solution would it take to make a 4 liter, 0.5M NaOH solution? (2M)(X) = (0.5M)(4) (2M)(x) = (0.5M)(4liter) x= (0.5M)(4liter)/2M x= 1 liter So, take 1 liter of 2M NaOH solution and mix it with 3 liters of H 2 O