Math

Common Symbols and Abbriviations

Order of Operations? Follow these simple rules: -PARENTHESES -EXPONENTS -MULTIPLICATION (left to right) -DIVISION (left to right) -ADDITION (left to right) -SUBTRACTION (left to right)

How do you remember it? Please Excuse My Dear Aunt Sally Now lets try using it! 3+5-2x2-(4-2)=? 3+5-2x2-(4-2) parenthesis first 3+5-2x2-2 multiplication second addition third subtraction last 4-2 subtract again 2 is your answer!

Measurement Systems METRIC (most common) HOUSEHOLD

Another Measurement System APOTHECARY

Weight and Volume Powdered drugs are measured on a scale and are in mg or grams. Liquid drugs are measured in cup, cylinder, or pipettes and are in liter or ml.

Metric System Metric system prefixes are applied to all units of measurement. To go from mass units to volume units, simply change grams to liters. The logic is identical! micro…mili..centi…gram..deca..kilo..meg

Brain Teasers!!! How many micrograms in a gram? 1 million How many milligrams in 10 kilograms? 10 million How many milligrams in half a centigram? 50

Doctors Orders Doctors will often order a patient to take a certain amount of drug, but may not specify exactly how many capsules/tablets, volume he should take. You will be responsible for calculating this. What are the 3 critical pieces of information? The doctor’s order (given) Strength of drug Units the answer will have

Now lets try one… The doctor has ordered that you take 30mg of Prozac before taking the next exam (LOL). The capsules are 10mg/capsule. How many capsules should you take? Order x strength of drug = order 30 x 1/10=3 capsules!!

Make a solution from a power Many medicines administered by healthcare professionals are actually drugs dissolved in a liquid vehicle. The same rule applies! Problem: You are asked to make 0.5 liter of an antibiotic solution. The final concentration of the solution should be 3 grams antibiotic/1 liter of water. How much antibiotic do you need? In what units is the answer ? Grams In what ratio is given? 3g/1L In what is the quantity to be converted ? 0.5 L

Lets figure it out! 0.5 Liter X 3g / 1 L = 1.5 grams of antibiotics So you take 0.5 liter x 3 grams of antibiotic Divided by 1 liter of water = 1.5 grams of antibiotics.

Parental Dose Problem: The doctor asks you to administer 300 mg of antibiotic each day. The antibiotic comes as a liquid mixture in a strength of 150 mg/500 ml. How much liquid do you administer each day? What units is the answer in? Ml What ratio is given? 150mg/500 ml What is the quantity to be converted? 300 mg 300mg x 500ml/150mg = 1000ml