# S E C Medical Mathematics C U S S E C Medical Mathematics C U S S 1.31 Apply mathematical computations related to healthcare procedures (metric and household, conversions and measurements.)

Objectives Recognize and estimate metric measures. Convert among units in the metric system. Convert among household measures and the metric system. Appreciate the value of using the metric system in health care. Health Care Applications Why do we use the metric system in health care? To align with the rest of the world To assure accurate and consistent communication in a healthcare

setting Because it is based on 10s, you can do some calculations in your head! Image from www.pocketnurse.com Its Really Very Simple

1 kilometer = 1 hectometer = 1 dekameter = 1 meter 1 decimeter = 1 centimeter = 1 millimeter = 1,000 meters 100 meters 10 meters 0.1 meter 0.01 meter

0.001 meter Were Going to Start with These 1 kilometer = 1,000 meters 1 meter 1 centimeter = 0.01 meter 1 millimeter = 0.001 meter How many meters?

1 meter 1 kilometer = ______________ 1000 meters 1 millimeter = ______________ 0.001 meter 1 centimeter =______________ 0.01 meter Make a Mental Picture Kilometer Track around football field = 400 meters How far for a kilometer?

Meter Centimeter Millimeter Using a meter stick or ruler, use your body to make a mental picture of 1 meter, 1 centimeter, and 1 millimeter. Can you do the math? How many millimeters in a centimeter? How many centimeters in a meter? How many millimeters in a meter?

10 100 1000 How many meters in a kilometer? 1000 How tall are you in meters (estimate)? 2 What about weight? 1 kilogram = 1 gram 1 milligram =

1,000 grams 0.001 gram Also referred to as mass. Make a Mental Picture Kilogram Gram About the weight of a half-full 2-liter bottle. The plastic top weighs 2 grams A can of soup contains 300 grams

Milligram Approximately 3 grains of salt. Can you do the math? How many milligrams in a gram? 1000 How many grams in a kilogram? 1000

How much did you weigh at birth in kilograms? What about liquid measures? 1 liter 1 milliliter = 0.001 liter 1 cubic centimeter (cc) = 1 milliliter (mL) Make a Mental Picture Liter You already know the volume of a 2-Liter bottle Milliliter

A 12 ounce can of soda is 354 mL One teaspoon is 5 mL Can you do the math? How many milliliters in a liter? 1000 How many milliliters in a coffee mug? 240 Estimation Game

Images from www.pocketnurse.com Number a sheet of paper from 1 10 When your teacher shows you an item, write down your estimate of the length, weight or volume, using the metric system. How did you do? Converting Grams Grams to milligrams multiply by 1000 or move decimal three places to the right 0.15 g = _____ mg 0.150 g = 150 mg 0.15 g = 150 mg

Milligrams to grams divide by 1000 or move decimal three places to the left 500 mg = _________ 0.5 g Converting Grams What would you do to convert grams to kilograms? 600 g = _________ 0.6 kg What would you do to convert kilograms to grams? 4.5 kg = _________ 4500 g

Converting Meters Meters to millimeters multiply by 1000 or move decimal three places to the right 2.54 m = _____ mm 2.540 m = 2540 mm Millimeters to meters divide by 1000 or move decimal three places to the left 1650 mm = _________ 1.65 m Converting Meters How would you convert meters to kilometers? 10,000 m = _________ km 10

How would you convert kilometers to meters? 4.559 km = _________ 4559 m Centimeter to meters? Move the decimal two places to the left. 10 cm = 0.1 m Centimeters to millimeters? Move the decimal one place to the right. 5 cm = 50 mm Converting Liters Liters to milliliters multiply by 1000 or move decimal three places to the right

1.25 L = _____ mL 1.250 L = 1250 mL 1.25 L = 1250 mL Milliliters to liters divide by 1000 or move decimal three places to the left 500 mL = _________ 0.5 L Metric Quiz 250 mg 1. 0.25 g = ______ 0.088 kg 7. 88 g = ________

1500 mm 2. 1.5 m = _______ 0.075 m 8. 7.5 cm = _______ 0.003 m 3. 3 mm = ________ 0.3 km 9. 300 m = ________ 10 mL 4. 10 cc = ________

10. 10 kg = __________ 10,000 g 0.002 g 5. 2 mg = _________ 11. 40 mg = 0.00004 _________ kg 6. 200 mL = _________ 0.2 L 12. 6 L = _________ 6000 mL

Congratulations! Time to Convert Household Weight 1 ounce (oz) = 0.028 kg or 28 g 1 pound (lb) = 0.454 kg or 454 g 1 kg = 2.2 lbs To convert lb to kg, divide the number of pounds by 2.2 145 lb 2.2 = 65.9 kg To convert kg to lb, multiply the number of kilograms by 2.2

25 kg x 2.2 = 55 lbs Now You Try It - Weight 0.168kg 1. 6 oz = ________ 100 kg 2. 220 lbs = _______ 3 lbs 3. 1362 g = ________ 8.8 lbs 4. 4 kg = _______ 448 g 5. 16 oz = _______ 10 oz 6. 280 g = ________

12 oz 7. O.336 kg = ________ Now You Try It Weight No Notes or Calculator 0.056kg 1. 2 oz = ________ 50 kg 2. 110 lbs = _______ 1O lbs 3. 4540 g = ________ 4.4 lbs 4. 2 kg = _______ 280 g

5. 10 oz = _______ 5 oz 6. 140 g = ________ 3 oz 7. O.084 kg = ________ Congratulations! Time to Convert Household Length

1 inch (in) = 0.025 meter (m) or 2.54 cm How many mm in 1 in! 25.4 1 foot (ft) = 0.31 meter (m) or 30.48 cm How many inches in a foot? How many feet in a yard? How many meters in a yard? 0.93 Sowhich is longer, a meter stick or a yard stick? Now You Try It - Length 0.15 m 1. 6 in = ________ 11 in 2. 27.94 cm = _______

1000 in 3. 25 m = ________ 124 m 4. 400 ft = _______ ft 5. 15.24 cm = ______ 188 cm 6. 6 ft 2 in = ________ 53.76yards 7. 50 m = ________ Did You Have Any Trouble? How do you convert centimeters to inches? To convert cm to inches, divide the number of centimeters by 2.54.

How do you convert centimeters to feet? To convert cm to feet, divide the number of cm by 30.48. Sometimes You Combine Formulas To convert meters to inches, move the decimal first and then use the cm in formula. 14 m = _________ in 14 m = 1400 cm 1400 2.54 = 551 in Testing Tip When taking a written medical math test, write down the conversions you know before you start the test.

We like to write the conversions we know on the bottom of the page. They become our personal conversion table. Rounding usually to the nearest 100th but be flexible. When its REALLY close, round again. 5.99998 would round to 6 Now You Try It Length No Notes or Calculator 0.3 m 1. 12 in = ________ 2 in 2. 6.35 cm = _______ 200 in

3. 5 m = ________ 62 m 4. 200 ft = _______ 2 ft 5. 60.96 cm = ______ 96.5 cm 6. 3 ft 2 in = ________ 10 yards 7. 10 m = ________ Congratulations! Time to Convert Household Volume

1 milliliter (mL) = 1 cubic centimeter (cc) 1 teaspoon (tsp) = 5 milliliters (mL) 1 tablespoon (tbsp) = 15 milliliters (mL) 1 ounce (oz) = 30 milliliters (mL) 1 cup = 8 oz = 240 mL 1 pint (pt) = 16 oz = 500 mL 1 quart (qt) = 32 oz = 1000 mL = 1 Liter (L) Isnt That Funny Math?

If 1 cup = 240 mL, and 2 cups equal one pint Shouldnt 1 pint = 480 mL instead of 500 mL? Why the funny math? The conversions arent perfect, but the medical community accepts the conversions we gave you on the previous slide. Now THIS is funny math! 3 out of 2 people have trouble with fractions. Now You Try It - Volume

4 cc 1. 4 mL = ________ 100mL 2. 20 tsp = _______ 4 tsp 3. 20 mL = _______ 120 mL 4. 4 oz = _______ 3 cups 5. 750 mL = _____ 4 pts 6. 64 oz = ________ 9 L 7. 9 qts = ________

Now You Try It Volume No Notes or Calculator 16 cc 1. 16 mL = _______ 50 mL 2. 10 tsp = _______ 8 tsp 3. 40 mL = _______ 90 mL 4. 3 oz = _______ cup 5. 120 mL = _____ 2 pts 6. 32 oz = ________

12 L 7. 12 qts = ________ Congratulations! Time to Convert Temperature Fahrenheit (F) to Celsius (C) = 0F- 32 x 0.5556 Celsius (C) to Fahrenheit (F) = 0C x 1.8 + 32 If you memorize those two formulas, temperature conversion is fairly easy. Get out your calculators! Now You Try It - Temperature 126.7 0C 1. 260 0F = _______ 0 0C

2. 32 0F = _______ 3. 4. 5. 39.2 102.6 F = _______ 0C 46.4 0 8 C = _______ 0F 89.6 32 0C = ______ 0F 32 0 0

0 6. 0 C = _______ F Round to the nearest tenth Now You Try It Temperature No Notes or Calculator 55.6 0C 1. 132 0F = _______ 1.1 0C 2. 34 0F = _______ 3.

4. 38.6 101.4 F = _______ 0C 50 0 10 C = _______ 0F 96.8 0 0 0 5. 36 C = ______ F 6. 50

0 122 C = _______ 0F Round to the nearest tenth