Quick and Dirty Guide to Medical Math: Module I

Medical Math Module 1
Spaced Repetition: Do not finish this module and never look at it again. Complete this module. Then, tomorrow, redo this module and THEN start module 2. Before starting module 3, go over module 1 and 2 again. I know it seems like overkill, but SPACED REPETITION is the only way human beings assimilate information. You have to see it till it becomes easy, and then you have to remind your brain that the information is STILL useful by seeing it again. Then, it will remember.

We’re going ABSOLUTELY AS SLOW AS POSSIBLE!
The first step is just getting comfortable and not freaking out. You can do this. We’re going to help by breaking it down into tiny steps. First, we’re simply learning to convert grams into milligrams.

1 Gram = 1000 mg (milligrams)
How many milligrams in 2 grams? 2000mg
How many milligrams in 3 grams? 3000mg
How many milligrams in 2.5 grams? 2500mg

Simply move the decimal point to the right 3 places (1.0g = 1000.0mg)
So look: 3.55g = 3550mg
We just moved the decimal point 3 spaces to the right to convert grams to milligrams. Just practice converting any number of grams into milligrams until you absolutely are bored by it. I promise we will walk you through every step. The key is to do every step until you are so comfortable with the tiny step, that you’re sick of it.
Convert the following Grams into Milligrams. Just write the number. Don’t add mg, commas or anything to it. (Ex: 1g = ____mg; answer is 1000)

Now, we’re going to it backwards! We’re going to go from milligrams to grams!
When you’re converting from bigger to smaller, you move the decimal point to the right. When you’re going from small (mg) to big (g), you just move it to the left!
Milli just means 1000th, so a milligram is 1000th of a gram. Therefore, 1 gram has 1000 milligrams in it. So we can say we have 1g or we can say we have 1000mg… its the same amount!
So, what if we only have half of that? What if we only have 500mg? How many grams do we have? Since 1000mg is the same as 1g, then 500mg will be half of a gram, or 0.5g.
Doing the math:
If 1 Gram = 1000 mg (milligrams), by moving the decimal 3 places to the right, then all we have to do to do it backwards is to move the decimal 3 places to the left!
Example: 1000mg = 1g.
So, how many grams in 2000mg? 2, right? Easy! We’re just moving the decimal point 3 places to the left.
1000mg = 1g
1500mg = 1.5g
3250mg = 3.25g
500mg = 0.5g
Simply move the decimal point to the left 3 places (1000.0mg = 1.0g)
So look: 3550mg = 3.55g
We just moved the decimal point 3 spaces to the lef to convert milligrams to grams. Just practice converting any number of grams into milligrams until you absolutely are bored by it. I promise we will walk you through every step. The key is to do every step until you are so comfortable with the tiny step, that you’re sick of it.
Convert the following Grams into Milligrams. Just write the number. Don’t add mg, commas or anything to it. (Ex: 1000mg = ____g; answer is 1)

Now, the other commmon measurement we will work with is converting milligrams and micrograms.
Just like 1 gram = 1000mg, 1 milligram (mg) = 1000 micrograms (mcg)
So, if I have 5mg, I have 5000 mcg.
If I had 250mg, I would have 250000mcg. Once again, we’re moving the decimal place 3 spaces to the right to convert to a smaller number.
See if you can get these right?
1mg = ______mcg (Answer: 1000)
2mg = ______mcg (Answer: 2000)
25mg =______mcg (answer: 25000)
0.5mg =_____mcg (Answer: 500mcg)
Ok, here’s a tough one…
1g = _______mcg
The answer is 1,000,000. Because you’re going from GRAMS to MICROGRAMS, you have to move the 3 decimal places for mg, then 3 more for mcg!
You won’t have to convert grams to micrograms very much in your career (if at all) but I just wanted to show you that you can do it.

When converting from mcg into grams, you’re going from smaller to bigger, so you just move the decimal 3 places in the other direction…left!
Example: 1000mcg = ______mg (Answer 1)

Now You Try!