Alright, let’s talk about how to convert

units of measure. Maybe the concept that is used the most

in any science class because almost every single problem is going to require

you to convert units in chemistry physics biology kind of whatever

converting units is a big one that never leaves once you learn it and you’ll see

lots of different ways on how to convert units and because it’s kind of just

using fraction math there are lots of different ways to show it lots of ways

to draw brackets or different things to help people remember it and the way that

I’m going to go over today is kind of the longest way possible this is the

anti shortcut way which sounds annoying but I think that this is the way that

fundamentally explains it and if you are struggling and if every time you have to

convert units you just find yourself flustered and lost you don’t know which

number to pick or where to put it this is the way that really explains that so

this is not the way that’s going to get done in like a minute but this is the

way that’s going to help you understand and even if you don’t know what’s

happening as long as you carefully follow all of these steps you’re going

to get the right answer so if you’re just starting out or struggling this is

the way for you and so let’s start we’ll be doing our practice problem how to

convert 16 centimeters into meters and so step one is to identify your

conversion ratio and so in every conversion problem we’re going from one

unit to another and there’s always some ratio that’s going to connect those two

and this is kind of how to find this is kind of more of an introduction on the

metric system or something else so we’re just going to start with

assuming that you know how to find your conversion ratio for this problem and so

that means that we have to know the relationship between centimeters and

meters and so that relationship is that a hundred centimeters equals one meter

and so this is our conversion ratio that’s step one we’re done we know that

this is how centimeters and meters relate to each other so step two write

your conversion ratio as its two possible fractions and what I mean

by that is that your equal sign is now going to become your fraction bar and so

for this are two possible options are 100 centimeters over one meter and then

our other option is one meter over 100 centimeters and so I made both of them

because I don’t know which one I’m going to need yet all I know is that I have my

conversion ratio and this equal sign is now going to turn into a fraction where

either one could be on top so that’s always what you’re going to do is just

make these two different fractions with both opposite options on top and so now

step three draw your given number as a fraction including units and this is

really important because every number is secretly a fraction whether or not it

shows it and so the number that we got in the problem is just written like this

16 centimeters and now we’re going to draw that as a fraction and so what that

means is that if there’s no fraction like seen immediately it means that this

is secretly a numerator and so if it’s secretly a numerator then when we draw

it out it’s going to be like this 16 and centimeters very important are both on

the numerator and our denominator is just one because remember that if our

denominator is one then really what we see on the numerator that just is our

total answer and so this step is really important and never drop the unit’s all

students want to drop units it’s just in their blood don’t do it especially in

these problems we’re converting units make sure that you know that you’re

centimeters is on the numerator it’s very important okay great so now that we

have all of our prep work done we’re ready to do the actual problem and so

step four pick the best conversion fraction multiply and solve okay so for

this first example I’m just going to set everything up so we have our 16

centimeters over one this is our actual number now

all written as a fraction and so step one or option one is that we just

multiply it with this guy this is the first conversion fraction that we made

so let’s just set that up and then we have another or situation because we

could multiply it with this guy so let’s set that guy up too so it’s our same

number or same number that’s getting converted 16 centimeters over 1 and now

we have this second fraction so one meter over 100 centimeters all right so

one of these is going to be correct and one of these is going to be wrong so now

let’s just do the math and solve so if we multiply across the top on the

numerator here we’re going to get 16 times 100 and so that’s going to be 1600

and then remember we have to multiply our numerator so this is not going to

cancel out we have two centimeters on top so that means that our answer for

this will be centimeters squared and then our ones are going to multiply

that’s just going to be one and then our meter didn’t cancel out or do anything

so that’s going to be still here so option number one we got 1600

centimeters squared over one meter now this is an ugly gross answer we don’t

want this so this was the wrong choice so now let’s see what the choice was

with the correct conversion fraction so over here we have and this is the most

important part our cancellation this centimeters is on top and this one’s on

bottom so we can cancel them out and so now we multiply it’s going to be 16

times 1 so just going to be 16 and our unit is going to be meters and then on

the bottom it’s just going to be 1 times 100 so that’s just going to be a hundred

and there is no unit on the bottom because centimeter got cancelled out so

now we have 16m over a hundred and just to simplify put it into a decimal or

calculator we get 0.16 and our unit is meter and so this is our correct answer

and let’s assume we’re taking a science class we have to do sig figs here so our

original problem had one two sig figs just one for each non zero and then our

final answer this is not a sig fig both of these are remember that leading zeros

are never sig figs so our final answer has two sig figs so that’s correct and

so in these problems our conversion ratios don’t really count as sig figs

you wouldn’t count any sig figs for this or this because it’s considered like a

perfect number so one hundred centimeters and equals one meter that’s

not a measurement we didn’t like go into lab and say okay we figured that out

that’s just kind of a perfect thing that all of science assumes so we don’t have

to use sig figs from those two numbers all right now let’s do a couple more

practice problems all right so starting with our first problem

convert point six eight five milligrams into grams so just going to do the same

four steps and do them really diligently and we won’t get misled into a wrong

answer so step one identify your conversion ratio so in this case we’re

comparing milligrams and grams and so the relationship is that a thousand

milligrams equals one gram all right and so now we’re going to write our two

possible conversion fractions so our equal sign just literally becomes a

fraction and so it doesn’t matter what you start with on top there’s only two

options since you only have two things so our two fraction options are a

thousand milligrams over one gram or one gram over a thousand milligrams all

right so one of these is going to be the conversion unit that we need alright so

step three draw your given number as a fraction including units and so I’d pick

this example because even decimals can secretly be fractions

so if you have a decimal just use it as normal and put point six eight five and

milligrams they’re all going to be on the numerator and then you can just

throw a 1 under it and that’s still completely fine and so just be really

careful make sure your units are still in the numerator and so now step 4

pick the best conversion fraction multiply and solve so we’re going to set

up our original problem number and now we have to pick what conversion fraction

is going to go right here which one is going to help us solve and so for that

we’re going to do a little bit of thinking ahead and our big goal here is

to cancel out milligrams the whole point of the problem is to get rid of

milligrams and put it into grams and so we can see if we put this guy in there

milligrams is going to be on the numerator and that means that you’re

going to end up with something milligrams squared and then our grams is

going to be on the denominator and that’s not right so what we don’t want

is to use that one and we do want to use this guy because we can see right here

this milligrams on the bottom is going to cancel out with the milligrams that

we have on top from our number so this is the one that’s going to help us out

so we can fill this in one gram over a thousand MiG’s all right and so now

let’s do some calculator math I don’t feel like solving this right now so we

plug that in and we get point zero zero zero six eight five and then our unit is

grams this cancels out and this is our number and so now let’s again assume

we’re doing it in a science class not a math class we’re going to then have to

do sig figs and so our original problem this doesn’t count the leading zero one

two three sig figs so we want our final answer to have three sig figs so none of

these leading zeros count one two three so this ended up in three

so this is correct and remember that in a conversion none of these are going to

count for sig figs we just ignore them the only one that was given to us only

one that’s a measurement is this first point 685 okay cool and now let’s do our

last example convert an eighth of a liter in to milliliters all right and so

step one identify your conversion ratio once again we’re just dealing with two

different units liter and milliliters so one liter equals a thousand milliliters

so our two conversion ratios and they’re two possible fractions are one liter

over a thousand mils or a thousand mils over one liter and so now we’re going to

draw our given number as a fraction including units and so once again I gave

you a different type of number to force you to think about where your units go

and what happens when you convert a number into a fraction and so this says

convert in eighth of a liter so if we just draw that out it’s going to be 1/8

and the way that you see unit’s written next to fractions is usually like this

they’re right in the middle so 1/8 of a liter and this is pretty typical but

it’s really important to know what that actually means because when we have to

assign that unit to a part of our fraction we have two options right we

could do this we could do one liter over 8 or we could do this one over 8 liters

and one is correct and one is incorrect and so the big thing to really know is

that unless stated otherwise your unit is on the numerator so this is the

correct one we were not told here that this was the denominator it just was in

kind of neutral it’s kind of hanging off to the side but it actually means this

not this so if we meant that it was 1 over 8 liters which is completely

possible that could be in a science problem or a math problem we would just

have to be told that it would have meant that in our original problem that would

have been shown okay so now we have our step three done

and so now we’re going to pick our best conversion fraction multiply and solve

so one liters over eight and I just use the parentheses because I think that

they kind of make it easy to see you don’t need to be using them and so we

have our two options and so now thinking ahead to which one is going to cancel

out so we want our leaders down here because that is the only way that

they’re going to cancel out right so our most important thing is to say which

conversion fraction allows us to get the leaders in the denominator because

that’s the way we’re going to get rid of it and make room for the milliliters and

so now if we go we look at our two different conversion fractions the only

one that has leaders in the denominator is this one which means this is the one

we have to plug in this is the one that’s going to allow the correct

cancelling and the right answer to appear all right so now let’s do our

multiplication and do some canceling out so if we cancel these guys out and we

know we’re going to end up in mill and so basically we have a thousand over

eight and that turns into 125 and so that’s our answer so just talk about sig

figs a little bit in this problem so we had it written up here as an eighth it

was just words not numbers and so the way that I run my classes is when you

see that it means that you don’t consider sig figs that you just consider

it to be an eighth is like a perfect number kind of like our conversion

ratios we wouldn’t consider one liter or a thousand mils to either them have sig

figs but I think every teacher kind of does it on their own so if you’re in

taking a test and you don’t remember what your teacher said and you see some

kind of word written out you can definitely ask them that’s fair game

there’s not one standard way that everyone should be doing that that’s all

I have for you today I hope you enjoyed this longer very detailed explanation of

how to convert units again I really think that if you store

with this topic this is the way that makes you think about every step that

doesn’t allow you to have a pitfall where you take a wrong turn this is

really the way that forces you to do it correctly even though it takes longer

but hey when you rather take longer and get the answer right then do a shortcut

you don’t understand and not know if you got it right this is the teacher nagging

side of me coming out I can’t control happens everybody starts teaching

chemistry I think anyway that’s all I have for you today I hope you enjoy this

video and have a good day

You're awesome! I don't have it down packed but this helped tremendously!

brobing and you don't write nice

how bad hand writing and i never see so bad hand writing but it helpful and sorry for this and please don't mind that i have please and math are very improtant for our life . write my comment and i write some more comment and please don't mind . i think your are aesome

Thank you very helpful!!!

This is a really complicated way and noone who uses the metric system daily use fractions to do conversions. You just move the decimal point. Example: convert 200 cm to meters, move the decimal point 2 places and you get 2 meters. That's the beauty and simplicity of the metric system. Just move the decimal point.

thnku it helped me alot

Thanks for the explanation…now I can help my niece with her homework,

80% of people are good in math and i belong in 13% 😎

Thank you so much for sharing your knowledge on conversions! This has helped me tremendously I have a much better grasp on the subject. Much appreciated!

plz make a video on chemical reactions in inorganic

I like ur presentation but use a LARGER font and also your conversion ratio I couldn't find that in any book???!

What about 8.32 * 10^-3 kg to grams?

This method is unnecessarily complicated. I personally would start with the conversion ratio but from there on its all different. 100cm = 1m (divide both sides by 100 to find 1cm) 1cm = 1m/100 (multiply both sides by 16) 16cm = 1m x 16 /100 therefore 16cm = 0.16m. A lot simpler imo.

Thanks for this video. I wasn't understanding this formula in my class, and I have to retake my test tomorrow because I initially failed it, but your explanation makes me feel confident that I can pass tomorrow.

Thank you for this channel. It seems like my chem professor won't be one to discuss things in detail. Your videos will be a cornerstone of supplemental instruction for me. You are amazing !!

Very Nice! THANK YOU for sharing!

Crazy teacher fuck you

confusing didnt learn anything

Thank you 😎😃😆😅😀😁☺🙂

To long got the answer by using 100cm =1m taking it away to get your answer.

Thank you so much! I was getting confused on how to set up the conversation equations! Studying for the state certification exams. I am certainly not going to be a math teacher!

amazing was that.

This is great. No point using shortcuts if you don't know what they're for.

ex battalion

I should be paying my tuition fees to you.

If you have an eighth and you put that in the calculator it gives you three sig figs, which is what you had in the answer.. can you do it that?

Sorry I got lost halfway, too many choices.Too much room for error and if your a complete maths biff how would you know that you multiply?

this video described it very well

Nice

Diosito me acompañe en mi examen 🙏🏻♥️

what is the sfs means ?

In the second example I thought you multiply when going from larger units to smaller ones?

This is exactly how my professor is teaching us conversions and I was really confused. You explained it well and now I have a better understanding :'D

tears of joyHow will you know if your going to put a 1000mg or 100mg in example #2?help

Thank you thank you thank you. I've seen so many conversions I just needed it explained fully and you have done that.

I can not thank you enough for taking time to put this video out in the universe. I have my conversion test today. It's an accelerated program and material was only introduced to us on Friday. Its Monday and we test @ 830 am . Its 6 am and I finally see the light ,THANKS TO YOUR TEACHING TECHNIQUE. AN AWESOME TEACHER CAN MAKE ALL THE DIFFERENCE THAT WILL EITHER MAKE OR BREAK A STUDENT. OUR INSTRUCTOR IS BREAKING THOSE OF US WHO JUST NEED IT PRESENTSED FOR VISUAL LEARNERS. I THINK WITH YOUR HELP IM GOING TO MAKE IT. MAY YOU BE BLESSED WITH ALL THE BEAUTY YOU DESERVE…. ✌

I'll be playing your video on repeat for my hour drive to school this morning. Thanks , again .