Transcript How big is BIG? Or How small is SMALL?

How big is BIG?
Or
How small is
?
SMALL
Do Now (Begin NEW week 2):
OBJECTIVE:
1. Describe quantities using factors of 10.
TASK:
1. Pass forward week 1 Do Nows
1. Make a “metric bingo” card. Draw a 3x3
square, and randomly place the prefixes G, M, k,
d, c, m, and µ in the boxes (note: 2 squares will
have duplicate symbols). See board for example.
Let’s Get This Straight.
• The SI (aka metric) system of measurement is
used in science. The unit of length is the meter,
m. 1 m = about 3 feet
• To the nearest “factor of 10,” you are about 100
m tall. (remember: 100 = 1)
• If you were 1,000 times
-3
SMALLER…(10 )
Homo
sapiens:
1-3 m height
• If you were 1,000 x
smaller, you would
be 1-2 mm in
size… (10-3)
• about as big as
this flea
1,000 times smaller than that? No
Way!
• Yes, way! In the last example, you were
about 1 millimeter tall. Scientists write that
number as 0.001 m, or 10-3 m.
• Factors of 10 are how science keeps track
of how big or small things are. Biologists
study living things (and parts of living
things) from 10-9 (nm) to 103 (km) in size.
3
If you were 10 m tall… KILO
• A blue whale would
easily fit in your
hand.
• The largest living
organism (The
Humongous Fungus)
covers an area with a
width of over 3 km!
The Humongous Fungus:
Armillaria ostoyae
• Found in trees and
soil across an area
of nearly 2,400
acres.
• Mass estimate
range: 7,500 tons
to >35,000 tons (~
107 kg)
• Age estimate:
1,900 – 8,650 years
On the other hand, at 10-3 m, milli
• A human
hair would
look like
this!
• You’d be
as big as
a single
grain of
sugar
1,000 times smaller than 1,000
times smaller!
• You’d be 10-6 m (1 µm) tall,
about as big as a small
bacterial cell
Catch a Cold!
• The softball sized object is a
model of the virus that causes
the common cold.
• If you were 10-6 m tall it would
be life-sized
When Good Protists Go Bad…
• If you were 10-6 m tall, cells like these
could SWALLOW YOU WHOLE!
Look closely!
• The bumps on the virus are proteins that
make up the outer layer of the virus.
• What is protein?
Proteins are BIG???
• YES! Proteins are huge molecules made
up of thousands and thousands of atoms.
In biochemistry, 10-6 m is
REALLY BIG!
CELLULOSE
(sponge)
DNA
ATOMS ARE more than 1000x smaller
than that! Chemistry is nano-scale
A quick review…
• 103 m tall: A blue whale fits in your hand. (kilometers)
• 100 m tall: your natural size. (meters)
• 10-3 m tall: human hair is as thick as a poster tube.
You
are the size of a single grain of sugar. (millimeters)
• 10-6 m tall: viruses are softball-sized, and you can get
eaten by a paramecium! (micrometers)
• 10-9 m tall: you can play catch with atoms! (nanometers)
Powers of 10, 1977
• http://www.teachertube.com/viewVideo.ph
p?video_id=119236
• Animation:
• http://htwins.net/scale2/
Scientific Notation
• How scientists and engineers do math with
really big and really small numbers
– Example: 93,000,000 mi = 9.3 x 107 mi
• Metric prefixes help too! (more on that
later)
– Example: 0.002 m = 2 mm
Basic Facts About Scientific
notation
• Positive exponents represent large
numbers.
– To convert a number into scientific notation
• Move the decimal place to the left until there is
only one digit left.
2,400  2.400 = 2.4
• Count the number of places moved. This is the
exponent
2,400 = 2.4 x 103
Basic Facts About Scientific
notation
• NEGATIVE EXPONENTS REPRESENT
SMALL NUMBERS
– To convert a number into scientific notation
• Move the decimal place to the right until there is only one
digit (not zero) to the left.
0.000,065  6.5
• Count the number of places moved. This is the exponent,
remembering SMALL NUMBERS HAVE NEGATIVE
EXPONENTS
0.000,065 = 6.5 x 10-5
To convert to standard Notation
• Do the process in reverse.
6.3 x
5
10
630,000
Assignments
• Become an expert at using factors of 10 to
represent big and small numbers.
– Complete the Factors of 10 worksheet.