The United States uses pounds, miles, and Fahrenheit for measurements, but the rest of the world uses the metric system. This video lesson will help you to convert from one to the other easily, so you can understand kilometers and kilograms, too.
Metric vs. U.S. Standard Units
In the United States, we use the U.S. Standard Units for measuring things, like distance, weight, and temperature. We use measurements, such as miles, pounds, and degrees Fahrenheit. But the rest of the world, for the most part, uses the metric system of measuring things. This system uses measurements, such as kilometers, kilograms, and degrees Celsius.
You can see these measurements in use whenever you are on the road. If you are traveling anywhere in the United States, you will see the speed limit signs posted everywhere that tell you the speed limit in miles per hour. If you travel outside the United States, these signs will show the speed limit in kilometers per hour. Look inside any car and you will notice that the speedometer shows both miles and kilometers. You can see that they are related to each other.
Scales show you that your kilograms and pounds are related. Thermometers likewise show you that your degrees Fahrenheit and degrees Celsius are related. Because they are related, we are able to convert easily from one to the other. This is the purpose of this video lesson. We are going to learn how to convert from one to the other system of measurement and back again with ease. So, get your thinking cap on and let's go.
From Pounds to Kilograms and Back
We begin with converting between pounds and kilograms, our measurement for weight. Get on a scale in the United States and you will most likely see your weight in pounds. Get on a scale outside the United States and you are most likely to see your weight in kilograms. Don't worry; we're not concerned about your weight here. All we are going to do here is learn how we can convert from one to the other.
It's actually quite easy because, in math, we have a handy-dandy conversion formula we can use. What is it? Let me show you. It is this: kg = lb / 2.2046, where lb is pounds and kg is kilograms. How do we use this formula? We use this formula to convert pounds to kilograms.
We plug in our pounds value and then divide by 2.2046 to find out how many kilograms we have. For example, to convert 150 pounds to kilograms, we plug in 150 into our formula for pounds and then divide by 2.2046 to get 68.04 kilograms. So, 150 pounds is the same as 68.04 kilograms. Pretty cool, huh?
Now to go from kilograms to pounds, we use the formula lb = kg * 2.2046, where we plug in our kilogram value and multiply it by 2.2046. For example, to convert 70 kilograms into pounds, we plug in our 70 where we see the kg and then we multiply by 2.2046 to get 154.32 pounds.
From Fahrenheit to Celsius and Back
Next, we have our temperature measures: degrees Fahrenheit and degrees Celsius. If you look at any thermometer, you can actually easily change between Fahrenheit and Celsius. And yes, of course, we have a conversion formula for this, as well.
The formula to convert Fahrenheit into Celsius is C = (F - 32) * 5/9, where F is Fahrenheit and C is Celsius. We use this formula the same way we used the formula for converting our pounds to kilograms. We plug in our Fahrenheit reading where we see the F, and then we calculate to find our Celsius.
Let's see how this works with an example. To convert 98.6 degrees Fahrenheit into Celsius, we plug 98.6 into our F, and then we subtract 32 to get 66.6. Then we multiply by 5, which gives us 333, and then we divide by 9 to get 37 degrees Celsius. So, 98.6 degrees Fahrenheit is the same as 37 degrees Celsius. This is considered our normal body temperature. As a note here, instead of multiplying by 5 and then dividing by 9, you can also skip a step by multiplying by 5/9.
To go back from Celsius to Fahrenheit, we use the formula F = (C * 9/5) + 32. For this formula, we plug in our Celsius measurement, multiply by 9, then divide by 5, and then add 32. For example, to convert 27 degrees Celsius, we plug in 27 for C. We multiply by 9 to get 243. Then we divide by 5 to get 48.6. Then we add 32 to get 80.6 degrees Fahrenheit. This is the temperature of a nice warm day perfect for picnicking. Like with converting Fahrenheit to Celsius, we can skip a step here by multiplying by 9/5 instead of multiplying by 9 and then dividing by 5.
From Miles to Kilometers and Back
Lastly, let's convert our measurements for distance, our miles and kilometers. To convert from miles to kilometers, the formula is km = mi / 0.6214, where km is kilometers and mi is miles. We use it just like our other formulas. To find our kilometers, we plug in our miles, then divide by 0.6214. For example, to convert 25 miles, we divide it by 0.6214 to get 40.23 kilometers.
Going the other way, converting from kilometers to miles, the formula is mi = km * 0.6214. So, for example, to convert 50 kilometers, we multiply it by 0.6214 to find that it equals 31.07 miles.
Now we are done. So, let's review. In the United States, we use the U.S. Standard Units for measuring things, like distance, weight, and temperature. We use measurements, such as miles, pounds, and degrees Fahrenheit. The rest of the world, though, uses the metric system of measuring things. This system uses measurements, such as kilometers, kilograms, and degrees Celsius.
Why don't we put our conversion formulas into a table for easy reference? Here goes.
|lb to kg
||kg = lb / 2.2046
|kg to lb
||lb = kg * 2.2046
|F to C
||C = (F - 32) * 5/9
|C to F
||F = (C * 9/5) + 32
|mi to km
||km = mi / 0.6214
|km to mi
||mi = km * 0.6214
Once you are finished with this lesson, you should be able to:
- State the conversion formulas for weight, temperature, and distance for US system to metric system and back
- Convert miles to kilometers, pounds to kilograms, and Fahrenheit to Celsius, and vice versa.