543-107 Nursing:  Clinical Care Across the Lifespan

Math Test Review / Study Guide

 

EQUIVALENTS

 

Weight:                       gram                             g                      1g = 1000mg

                                    milligram                       mg                    1mg = 1000mcg

                                    microgram                    mcg                  1mcg = 0.001mg

                                    kilogram                       kg                    1kg = 1000g

                                                                                                1kg = 2.2 lbs

                                    pound                           lb (#)                1lb = 16oz

 

                                    grain                             gr                     gr i = 60mg

                                                                        ss                     ss = ˝

                                                                                                gr ss = 30mg

 

Volume:                      liter                               L                      1L = 1000ml =1000cc

                                    milliliter             ml                     1ml = 0.001L = 1cc

                                    cubic centimeter            cc                     1cc = 1ml = 0.001L

                                    teaspoon                      t                       1t = 5ml = 5cc

                                    Tablespoon                  T                      1T = 3t = 15ml

                                    ounce                           oz                     1oz = 30ml = 30cc

                                    cup                               cup                   1cup = 8oz

 

Length:                       meter                            m                     1m =100cm=1000mm

                                    centimeter                     cm                    1cm = 10mm = 0.01m

                                    millimeter                      mm                   1mm = 0.1cm =.001m

                                    inch                              in.                     1in = 2.5cm

 

COMMON FORMULAS

 

Dosage Calculations:

·        D/H x Q = X               D = dosage desired

                                                            H = dosage on hand

                                                            Q = quantity (amount on hand)

 

·        Ratio-proportion:       Dosage on hand                     Dosage desired

                                                            Volume on hand                         X volume

 

                                                                        mg                   mg

                                                                        ml                    X ml

 

IV infusion times/rate per hour:

           

            Total volume              Total hours

                 ml/hr

           

            Total ml ordered        ml/hr

            Total hr ordered

 

Practice Problems

 

1.         60 lb =              kg

 

2.         72 kg =              lb

 

3.         6500 g =             kg

 

4.         7 lb 7 oz =             kg

 

 

5.         gr iiss =              mg

 

 

6.         Order:             40 mg p.o. furosemide stat

            Supply:            20 mg tablets

            How many tablets would you need?

 

 

7.         Order:             Heparin 5000 units SubQ b.i.d.

            Supply:            Heparin 20,000 units per ml

            How many ml would you give for each dose?

 

 

8.         Order:             Gentamycin 60 mg IM Q 6h

            Supply:            Gentamycin 80 mg per 2ml

            How many ml would you give for each dose?

 

 

9.         Order:             Potassium 10 mEq p.o. stat

            Supply:            Potassium 20 mEq per 15 ml

            How many ml would you give?

 

 

10.       Order:             500mg Ancef IV Q 8h

            Supply:            2 g in 5ml

            How many ml would you need for one dose?

 

 

11.       Order:             Digoxin 0.5mg p.o. now

            Supply:            Digoxin 125mcg tablets

            How many tablets would you give?

 

 

 

12.       Order:             Atropine sulfate gr 1/100 IM stat

            Supply:            Atropine sulfate in 20 ml vial labeled 0.4 mg per ml

            How many ml would you need?

13.       Current IV is on an infusion pump.

            Order:             3000ml D5W over 24 hours.

            How much fluid will go in each 8 hour shift?

            What will the flow rate be (ml/hr)?

 

 

14.       Current IV is on an infusion pump.

Order:             Ancef 1 gram in 50ml 0.9% NS to be given over 30 minutes.

What rate (ml/hr) will the pump be set at?

 

 

15.       An antibiotic is mixed in 100ml D5W.  The infusion pump is set at 150ml/hr.

            How long will it take for the antibiotic to infuse?

 

 

16.       1000ml bag of 0.9%NS was hung at 0800 and is infusing at 125ml/hr.

How long will this bag last?  What time will a new bag need to be hung?

 

 

17.       Order:             Ancef 500 mg IM Q 4h.

            Supply:            Ancef 1g vial ( in powdered form).

                                    The label reads:  Add 3.7 ml of sterile water to yield 250 mg/ml

                                                                

            How many ml will you need for one dose?

 

 

 

18.       Order:             Valium 2.5mg IM Q 4-6h prn, agitation

            Supply:            Valium 10mg/2ml

            How many ml do you need for one dose?

 

 

 

19.       Order:             Vancomycin 40 mg/kg/day

            Child’s weight:           55 lbs

            What is the daily dose of medication for this child?

 

 

 

 

20.       Order:             Ampicillin 25 mg/kg/day.

            Supply:            Ampicillin 100mg/ml

            Child’s weight:           44 lbs.

            What is the daily dose of medication (mg) for this child?

            How many ml do you need for the daily dose?

 

 

Practice Problems:  Answer Key

 

1.                 27.3 kg

2.                 158.4 lbs

3.                 6.5 kg

4.                 3.4 kg

5.                 150 mg

6.                 2 tablets

7.                 0.25 ml

8.                 1.5 ml

9.                 7.5 ml

10.            1.25 ml

11.            4 tablets

12.            1.5 ml

13.            1000 ml / 8 hr shift; 125 ml/hr

14.            100ml/hr

15.            40 minutes

16.            8 hrs; 4 pm or 1600

17.            2 ml

18.            0.5ml

19.            1000 mg

20.            500 mg; 5 ml

 

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