Transcript The Inch and how it is built

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The Inch
and How it is Built
Skill,
Precision
and
Reading the English
Standard scale to a
sixteenth of an inch.
The Inch
is the standard small unit
in the English Standard
measuring system.
The inch is thought
out in an common
sense way that
makes it easy to
understand and use…
if you take a bit of time
to learn about its parts.
The Inch
uses only a few
fractions.
Some of the
fractions NEVER
appearing in the
inch are:
1/3, 1/5, 1/6, 1/7, 1/9…
apply it here!
You probably know a lot
about measuring already.
Mastering this
measurement skill
is not as hard as
you might think.
Lets make sure you remember
some important fraction terms:
The names of the fraction
numbers are:
Numerator
Denominator
Numerator: What is the
NUMBER of the inch parts
we are talking about?
This number is always an
odd number. If it is an even
number, REDUCE the
fraction.
Denominator: This
DENOTES the total number
of parts in the fractional
division.
The only denominator
numbers are:
1, 2, 4, 8 and 16!
And now the star of our show:
The English Standard
Inch.
And how the inch
unit is divided!
The blue drawing represents a
small part of an English Standard
ruler graduated in inches.
We are looking at the ruler
around the 27and 28 inch marks.
Whole inches are good for
measuring many large things…
but for most uses:
we need more precision!
To get a higher degree of accuracy,
we need to divide the whole inches
into smaller parts.
Where is the common sense
place to put a dividing line?
This divides the space into two
equal parts.
One
Division
One
Division
1/2
We need a fraction to indicate the middle
OneThink
half:
one
ofhave
thejusttwo
division.
of the
line we
drawn as 1 of the
2 divisions.
divisions!
What is the name of this fraction line?
1/2
This is the common sense way inches
are divided up to get more precision.
Empty measurement spaces are divided into two equal parts.
1/2
If both of the two division spaces are
divided into two equal spaces, what will
the total number of inch divisions be
now?
4!
The names of the fraction lines are:
1/4 and 3/4
Where are the measurements located on the scale?
1/2
The two fractions represent:
1 of the 4 divisions and 3 of the 4 divisions.
The 2 of the 4 divisions line (2/4) is reduced!
More precise measurement is still
Empty measurement spaces are
needed.
still being divided into two equal parts.
1/4
3/4
How many total inch divisions
are there now?
8
What are the fraction names of the
new lines?
They are all 8ths…..
1/8
3/8
5/8
7/8
Have you noticed how all the fractions do not
Measurement
fractions
with numerators?
even
have
even numbers
for their
numerators must be reduced!
Yes! (maybe)
We have arrived at the final division of
If we divide the 8ths into two… how
spaces.
many total divisions will we have?
1/8
3/8
1/8
3/8
5/8
5/8
7/8
16
7/8
We better get out our high powered
TECH GOGGLES to see them!
(whew!)
Here are the 16th lines
If we divide the 8ths into two… how
many total divisions will we have?
1/8
3/8
1/8
3/8
5/8
5/8
7/8
16
(whew!)
7/8
We better get out our high powered
TECH GOGGLES to see them!
There are only 8- 16th measurements!
Here are the 16th Fractions:
3/16 5/16 7/16 9/16 11/16 13/16 15/16
If we1/16
divide
the 8ths into two… how
many total divisions will we have?
1/8
3/8
1/8
3/8
5/8
5/8
7/8
16
(whew!)
7/8
We better get out our high powered
TECH GOGGLES to see them!
That isn’t so bad, once you understand it!
27
28
Lets look at a different English Standard ruler.
We are still looking at the 27 and 28 inches (“)
area of the ruler.
It is read just like the one we have just
learned about.
27
28
The inch divided into sixteenths is
one the standards of precision for
the entire construction industry.
If you can measure sixteenths,
you can build almost anything!
27
28
Can you identify the indicated
measurements?
27
28
Method 1: Remember (memorize)
what the lines indicate and identify the
measurement.
It is not difficult to memorize ALL
16 measurements if you try.
1/16 3/16
5/16
1/8
27
7/16
9/16 11/16 13/16 15/16
3/8
5/8
¼
7/8
¾
1/2
28
Here are the 16- inch measurement
fractions:
As you use this skill, you will memorize
the measurements without trying!
1 234 5 6 7 89
27
28
Method 2: Count the number of
lines from the whole line and
make a fraction.
9/16 of an inch (9/16”), 9 of the 16.
This measurement is 27- 9/16” (inches)
1 2 3 4 5 6 7 8 9 10
27
28
Here’s another: Count the
number of lines, if the numerator
is even, you must reduce the
fraction! 10/16”, reduced to 5/8”.
This measurement is 27- 5/8” (inches)
12345678
27
28
The skill continues:
Count the number of lines…
Did you get
Make a fraction with the count number as
numerator….27-½”?
16 is the denominator…
Do you reduce? What is the answer?
12345678
27
28
If you have started to
memorize the lines, you
knew this answer without
all the counting work!
1 2 3 4 5 6 7 8 9 10 111213 14 15
27
28
You are getting HOT now….
Count again!
Make a fraction with the count
number as numerator….
Do you reduce? What is the answer?
How about
27-15/16”?
27
28
Here is the last practice try:
Look at the indicated measurement.
How
about
I’m not going to number this one for you!
27-7/16”?
Do you know
it?
What is the answer?
27
28
Reading measurements 100%
of the time…
is an important skill to master.
There just 16 fractions used in
this level of inch precision
measurement.
It is an important skill to be able
to accurately measure 100% of
the time.
Technology depends on precise
measurement to be able to do its many
jobs.
27
28
Have you earned
a new skill?