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Pharmacy Tech Math - Alligation tutorial


Alligation math is a little known short-cut used by pharmacy techs and pharmacy students. It's also known popularly in pharmacy tech school as tic-tac-toe math.

Here's the next steps in how to work an alligation:



( Cont'd from previous page )

Step #4

So, now the amounts of the differences you found become the "Parts" of the % directly across the grid from it.

alligation math

Parts of the 3%



 → Parts of the 1%


Step #5

alligation grid

On your paper, write

Parts of  ___%

Then,

Add up the total "Parts"


Step #6

Now, take a look back at the question and look for the total volume needed.

alligation math


On your paper, to the left of number of parts, write

the needed volume

Then,

A division sign 


Step #7

Alligation Directions

Do the Math:

Now, you've divided the final solution volume into "Parts".

In this case, there's 125mL per part.


Step #8

Alligation Directions


Now, go back up to the "parts" and write the volume per part.

The Answer:

The question asked how much 3% to use. So, that's :1 part X 125mL =

125mL of the 3%


Here's what your paper should look like when done

alligation math


Now, go to:

 Alligation Math II - additional explanation




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