Hello, this is Miss O’Keefe.
You are viewing the metric conversion notes for my eighth-grade physical science class To help you with your notes, you should have
note sheet you received in class. The note sheet has seven blocks
making a staircase down from left to right, and two arrows. One in the upper right
and one in the lower left. In the center block, write the words
“Base unit.” Under that block write
“Meter, liter, and gram” These are the root units.
Like root words, they do not contain prefixes or suffixes.
Each represents a specific measurement. Meters are the unit for distance or length.
Liters are the unit for liquid volume. And grams are the unit for mass or weight.
We will be using each of these throughout the year. so it is important
for you to be able to convert these units from one size to another.
So let’s get started! When converting units, the placement
of the decimal point is what we are changing. In the bottom left corner is an arrow
pointing to the left. Inside it write, “To convert to larger units”.
This means, that as you move the decimal point to the left
the unit values are larger and larger For example, if we have 1000 meters,
Meters is a base unit. and move one, two, three, blocks to the left,
we have our first prefix kilo-. Kilo means one thousand.
This means from our original 1000 meters Moving the decimal point
One, two, three steps to the left We have one kilometer. A kilometer
is very large compared to a meter. If you were to run two and ½ times
around a standard running track, that would be one kilometer.
It is abbreviated km Kilo=k, m=meter.
Now, in the top right corner is an arrow pointing to the right. Inside it write
“To convert to smaller units”. As you move the decimal point to the right,
you move to smaller and smaller unit values. Let’s continue with completing
our staircase of prefixes. Moving to a prefix ten times smaller
than kilometers, move the decimal point One step to the right. This is a hectometer.
The prefix hecto means one hundred. So how many meters are in a hectometer?
That’s right. One hundred. A hectometer has the abbreviation h.
So a hectometer is hm. Ten times smaller than a hectometer
and ten times greater than a meter is deca, a prefix meaning ten.
For example the word decade. There are ten years in one decade.
So we have 10 meters in one decameter Is the deca is abbreviated da.
I’m going to pause here to demonstrate how you can convert a larger unit size
into a smaller unit size or vice versa. This all depends upon your starting
and ending prefixes. For example, if I have 10 decameters,
to convert this to kilometers, move the decimal point, two steps to the left.
This gives us 0.1 kilometers. But, to convert the same
10 decameters into meters, move the decimal point
one step to the right. This gives us 100 meters.
It’s important to recognize the size of the distance has not changed.
Only the placement of the decimal and the name of the unit we are using has.
As we continue, to the right of the base units the first prefix is deci.
Deci means one tenth or ten times smaller. Its prefix abbreviation for deci is d.
Centi is the prefix for one hundred times smaller.
An example of this is centimeter. One centimeter is 100 times smaller
than the base unit, meter. The way I remember this prefix is to remember
that there are 100 years in a century. The prefix abbreviation for centi is c.
Finally, the last prefix we have Is milli, as in millimeter.
Milli means that size is 1000 times smaller than the base unit.
From the base unit you move the decimal one, two, three steps to the right. A
millimeter is very small compared to a meter. About the thickness of your fingernail
All of these prefixes, Kilo, hecto, deca, deci, centi, and milli
have been used with meter as the base unit. They are also used with the other
base unit grams and liters. For example, kiloliters, milliliters
centigrams and milligrams. Finally, the movement of the decimal point
from larger to smaller size units or smaller to larger units is the same practice.
Use the following three steps. Number one, determine your starting point.
Number two, count the number of “steps”, or steps to your end point.
Number three, move the decimal the same number and in the
same direction of your “steps”. Let’s try a couple of examples.
Convert 4 kilometers in to meters. Number one, our starting unit is kilometers.
The end unit is meters. That means we move the decimal
from the prefix kilo one, two, three steps to the base unit meters.
Giving us an answer of 4000 meters. Now let’s convert 4 milliliters into Liters.
Milli is our starting point. To get to the end point, liters
The decimal has to move the decimal one, two, three steps to the right.
Giving us an answer of 0.004 Liters. These are the basics for converting
metric units from one size to another. We will be practicing this more
the next few days and throughout the year. Be sure to review your notes and bring them
to class. See you then!