The Metric System and Metric Conversions Why Use

The Metric System and Metric Conversions

Why Use The Metric System? n It is neutral and universally understood. n It uses standards that can be replicated by scientists working in any nation. n The decimal nature of the metric system makes conversion between metric units simpler. n Prefixes serve as convenient modifiers for metric units.

SI Units * *Not actually an SI unit, but commonly used.

Scientific Notation A way to express very large and very small numbers. n. A form of shorthand. n Write 2. 03 x 1018 instead of n 2, 030, 000, 000 n These two numbers are identical; just written a different way. n Like 2 + 3 is the same as writing 5.

Scientific Notation Powers of Ten n 101 = 10 n 102 = 10 x 10 = 100 n 103 = 10 x 10 = 1000 n 104 = 10 x 10 = 10, 000 n 105 = 10 x 10 = 100, 000 n And so on. . .

Scientific Notation Negative Powers of Ten n n 10 -1 = 1/10 = 0. 1 10 -2 = 1/10 x 1/10 = 1/100 = 0. 01 10 -3 = 1/10 x 1/10 = 1/1000 = 0. 001 10 -4 = 1/10 x 1/10 = 1/10, 000 = 0. 0 001 And so on. . .

Prefixes n Positive powers of ten: – kilo(k) = x 103 = x 1000 – Mega(M) = x 106 = x 1, 000 – Giga(G) = x 109 = x 1, 000, 000 n Negative powers of ten: – – centi(c) = x 10 -2 = x 0. 01 milli(m) = x 10 -3 = x 0. 001 micro(μ) = x 10 -6 = x 0. 000 001 nano(n) = x 10 -9 = x 0. 000 001

Prefixes Express 1 km in m. – kilo = x 1000 – 1 kilometer = 1000 meters n Express 1 mm in m. – milli = 0. 001 – 1 millimeter = 0. 001 meter n

Prefixes n 1, 000 phones = ? ? ? – 1 Megaphone (get it? ) n 0. 000 001 phones = ? ? ? – 1 microphone n 0. 000 001 scopes = ? ? ? – 1 microscope Metric prefixes are even used in literature: n 2000 mockingbirds = n – 2 kilomockingbirds

Prefixes So many. How can I remember which is which?

Centi How many pennies does it take to make up a dollar? 1/100 of a dollar What another name of a penny? Cent

More Money There are two prefixes that start with D Deca- 10 Deci- 1/10 When you see a D, think of a dime Because both of the d’s deal with 10 And the smaller has the I, just like dime

We also can use time to help us remember 10 years Decade 100 years Century

Micro- stands for 10 -6 or 0. 000001 or 1/1000000

Nanotechnology – really, really small technology Nano is 10 -9 So, also think nano = nine

Looking at mp 3 players and computers to remember other prefixes • I have a 60 gig hard drive. • My old mp 3 holds 512 MB of music. • My new i. Pod nano holds 8 GB • A blank CD-R holds 700 MB of music. • Mp 3’s are about 5 MB • The i. Pod nano picture I used in this presentation is 468 KB KB = kilobyte = 1000 bytes MB = megabyte = 1000 KB or 1000000 bytes Gig = gigabyte = 1000 MB or 100000 bytes