hello this is billy davis this is unit two video one of the math calculations for a healthcare professional class today we're going to be talking about measuring perimeter solutions using different syringes and using metrics middle equivalence units and ratio dosages we're going to start with decimals than metrics this unit is going to be broken into separate videos because blackboard does have some limits on uploading videos so if it's a long video it just takes too long to upload so this is going to be broken down into different segments so for decimals most of the medication calculations we're going to have to do will have some kind of decimal calculation in it you have to be comfortable with working with decimals when you do the calculations or you can make a mistake and overdose someone or underdose them we use decimals daily when we're doing the drug calculations and the metric system is what is almost always used in the hospital to do calculations and it's a decimal based system so the location of a digit relative to the decimal point determines the value now what that means is that if we look at a number like 1542.567 the whole number uh from the math classes we've had all through school uh we have the whole number is 1542 then you have the decimal point that separates the the decimal fraction of it the first spot is the tenths the second spot is the hundredths the third spot is the thousandth usually we don't go past thousands when we're doing uh drug calculations but it's important to remember these positions decimal then tenths hundredths thousandths now when we are using decimals we always use a zero as a placeholder uh to i'm sorry this is that there's typo here it says to the right of the decimal but it should be to the left of the decimal so if we have uh if we're giving 0.25 milligrams of medicine we always put the zero in front of it not just right .25 because we have sloppy handwriting we have uh the chance to misread things so we put the zero there as a placeholder just so we will know that it's uh 0.25 milligrams and not 25 milligrams now when we round decimals uh i kind of gave you a cheat sheet it should be in the files that are uploaded to blackboard but if you'll look it'll give you some examples of rounding up and basically the rules that we're looking for in the math class most of the time we will say round to the nearest tenth so if you have 10.34 that's going to round down to 10.3 but if you have one that ends in five or higher it goes up to the next so 10.35 rounds up to 10.4 just remember five or higher at the end rounds up to the next highest number occasionally we will say round to the nearest hundredth we do this a lot in the body surface areas so if you have 8.799 that's going to round up to 8.80 and 10.543 would round up to 10.54 so we're going to talk about uh metric notations and how to write things in just a little bit but usually we convert uh metric units from grams to milligrams to micrograms by moving the decimal you're not going to get away from the metric system if you go into health care because this is the most commonly uh used system for measuring uh medication doses in healthcare altogether so because of that it's really essential that you know how to convert units in the metric system to get the dosages right when we look at the basic units of the metric system we have the meter and that's measurements for height length the circumference of a leg wound sizes grams deal with weight and leaders deal with volume the last two were the ones that we use a lot in most basic drug calculations there are some others where we'll use meters if we have to calculate body surface area but we'll get to that in a little bit so just another view of it if we're looking at length basic unit is a meter the abbreviation is m weight is a gram and uh we'll use g or gm in this but we really prefer that you use g the volume measure is the liter this is for fluids and abbreviation is a capital l the metric system is based on multiples of 10 and the prefix before the basic unit like meter gram leader the prefix is what indicates the size now there are lots of them we have excepted tara giga we are not going to deal with all of those the ones that we are going to look at usually are kilograms uh for weight the centigrams or or centimeters for length uh milla and micro usually for drug calculations so in the columns on the right i just broke it down for you with weight for a person we usually look at kilograms with medication weights we look at grams milligrams and micrograms length we look at centimeters usually for a person's height and millimeters for small measurements like small wounds when we're doing fluid volumes we always look at liters and milliliters the nice thing is that the prefixes we typically use move the decimal spot three spaces to the left or right this doesn't include the centimeters but if we have uh let's look at grams if we have one gram and we move to kilograms it's going to move the decimal spot three spots milligrams from grams three spots micrograms from milligrams three spots so basically kilo is the larger size the million micro are the smaller sizes and when we're moving the decimal points we uh just have the basic rule if you're moving from a larger to a smaller unit move the decimal point to the right and if you're moving from smaller to larger move the decimal point to the left so let's look at a calculation here we're going to start off with a base unit of one gram and we're going to change one gram to milligrams so we're going to say that we have the one what we do is move the decimal spot three points to the right so we add three zeros to the end so one gram equals one thousand milligrams let's go a little further how many micrograms would be in a gram well from the last one we know to get from uh one gram to milligrams we're going to move the decimal three spots but when we get to the milligrams we also have to move it three more spots to get to the micrograms so one gram is essentially one million milligrams so just remember you move the decimal spot three spots typically for each one we use so if we go backwards uh how many grams would be in a milligram so we start off i'm going to just note it like this we have one milligram so where is the decimal spot going to be it's going gonna be to the right of the one so since we're converting uh remember the previous slide we're going from uh smaller to larger so we're moving to the left so that decimal spot is going to be three spaces to the left so what we do is uh move it one two three so we have zero point zero zero one grams one milligram equals one thousandth of a gram now why is the zero at the left on the left side of the decimal spot to show it as a marker or a holding spot so that we don't confuse this for something else so always write whenever you have something less than a whole number uh put the zero there to just to differentiate so we'll know so let's do some practice this is similar but we're going to look at leaders this time same basic principles so if we convert 4 liters to milliliters what do we do well we know that we're going to move the decimal three spots to the right so we have four liters so four point and then we know it's gonna be three spaces that we move the decimal spot over so 4.000 decimal spots at the end equals 4 000 milliliters all right that's going to be all of it for video one we're going to continue in a few other videos in this section like i said before with blackboard and the upload limits it has it's easier just to break it down this way so watch the rest of the videos and if you have any questions let me know