Pharmacy Math

Pharmacy

Math​

By Stephine Molina

​Pharmaceutical Calculations

• Basic arithmetic is always involved in some manner in the solving of pharmaceutical calculations.

• Perfecting basic mathematical functions will help to attain the goal of 100 percent accuracy desired in pharmacy.

• Because of the need for 100 %, no partial credit will be given for setting a problem up correctly if the answer is incorrect.

• In pharmacy, the correct answer is more important than the method.

Pharm Tech Class | Feb. 2022

Pharmacy Math

COMMON FRACTIONS, DECIMAL FRACTIONS AND PERCENT

Half is a half is a half​

A Half can be written...
As a fraction:	1/2
As a decimal:	0.5
As a percentage:	50%

​

Percent	Decimal	Fraction
1%	0.01	1
5%	0.05	1
10%	0.1	1
12½%	0.125	1
20%	0.2	1
25%	0.25	1
33	0.333...	1
50%	0.5	1
75%	0.75	3
80%	0.8	4
90%	0.9	9
99%	0.99	99
100%	1
125%	1.25	5
150%	1.5	3

Conversion

From Percent to Decimal

​

To convert from percent to decimal: divide by 100, and remove the "%" sign.

The easiest way to divide by 100 is to move the decimal point 2 places to the left.

 

Steps	Example
Convert 80% to a decimal (=80/100):	0.8
Write down the decimal "over" the number 1	0.8 / 1
Then multiply top and bottom by 10 for every number after the decimal point (10 for 1 number, 100 for 2 numbers, etc)	0.8 × 10 / 1 × 10
(This makes it a correctly formed fraction)	= 8 / 10
Then	4 / 5