The Wonderful World of Metrics!

Introduction

The metric system is a different way of measuring things. The practice is the same, but different units are involved.

Can you think of any metric measurements that you have seen or heard?

The “Basics”

The metric system uses SI base units as a foundation. Those units are…..

Meter (m) – a measure of distanceLiter (L) – a measure of volumeKilogram (kg) – a measure of mass

(this is the only one that uses a prefix! More on that soon…)

Second (s) – a measure of timeKelvin (K) – a measure of temperatureMole (mol) – a measure of an amountAmp (A) – Measure of current

The “Basics”

Every measurement will include one of the base words.

The metric system uses Prefixes too.

Every prefix is related to the base units. But how is that possible…

Pioneering the Prefixes

Lets start with the prefixes for large measurements….

KILO (k) 1 kilometer = 1000 metersHECTO (h) 1 Hectoliter = 100 litersDECA (da) 1 Decagram = 10 grams

Remember Meters, Liters, Grams, and Seconds are the base units. They will be in every measurement.

Pioneering the Prefixes

How about the small measurements…DECI (d) – 1 decimeter = 1/10 meterCENTI (c) – 1 centiliter = 1/100 literMILLI (m) – 1 milligram = 1/1000 gram

Remember, these prefixes are always added to the base root word

But that’s so confusing….isn’t there an easier way to remember all this?

Good ol’ King Henry

King Henry Died by Drinking Chocolate MilkKilo Hecto Deca Base Deci Centi

MilliCan you Think of your own?

Converting Skillz

When you are converting from one unit to another unit First figure out what you are starting with Then where (which direction) you are going!

If you move to the right (aka big to small) then you move the decimal to the right.

If you move to the left (aka small to big) then you move the decimal to the left.

Practice makes Perfect!

Try this one. 1 meter = ______ hectometer1st- Figure out your starting point and where

you are going!

K h da b d c m2nd – Find the Decimal and move it the same

way and number you moved in step 1.

Practice makes Perfect!

And this one. 2.5 kilograms = ______ grams1st- Figure out your starting point and where

you are going!

K h da b d c m2nd – Find the Decimal and move it the same

way and number you moved in step 1.

Practice makes Perfect!

Last one! 17.504 deciliters = ______ decaliters1st- Figure out your starting point and where

you are going!

K h da b d c m2nd – Find the Decimal and move it the same

way and number you moved in step 1.

Precision vs Accuracy

Precision A measure of the degree to which the measurements

made (and made in the same way) agree with each other

Accuracy

Degree to which the experimental value agrees with the true or accepted value

So, can measurements be precise without being accurate?

Precision vs Accuracy