Representation of Numbers (Part
3)
THE
"NATURAL" INTERPRETATION
Technical Point: In the previous section, we
explored a possible interpretation of the language, WHOLE
BINARY. Although there are an endless number of possible
interpretations for this language, we've been using WHOLE
BINARY which in itself has no meaning to also include the
natural interpretation presented in the last section. We will
continue with this slight abuse of notation to avoid
introducing further definitions. This notational abuse is
actually very common as we often associate a language with its
natural meanings (e.g. associating the English language with
the "natural" meanings of words such as 'water' being a
(clear) liquid).
The important point here is that a language in itself does
not come equipped with an interpretation. Why is this
interpretation of WHOLE BINARY so "natural" then?
Well, natural here means commonplace rather than what would be
your first intuitive idea for a representation of a number.
In fact the idea of different columns representating different
numbers (weighted columns) was far from the first
representation. However, as you proceed through this tutorial
series, you will see why this type of interpretation of is
very useful.
INTERPRETING NUMBERS IN WHOLE BINARY
In the previous section, we built up numbers by increasing
by one each time. However, we want to use the observations
from before to interpret numbers in WHOLE BINARY so
that we don't have to increase by one starting from zero until
we reach the number that we're trying to interpret. Let's
consider an example.
Example: To interpret 101001 in WHOLE BINARY,
we put it in Section 2's concluding table that was built up
from the observations:
| WHOLE BINARY COLUMN PLACE
NAMES |
| one thousand twenty-fours |
five hundred twelves |
two hundred fifty-sixes |
one hundred twenty-eights |
sixty-fours |
thirty-twos |
sixteens |
eights |
fours |
twos |
ones |
| |
|
|
|
|
1 |
0 |
1 |
0 |
0 |
1 |
From the table we can see that we have one package of ones,
one package of eights, and one package of thirty-twos, so by
JOINING THEM TOGETHER, we have thirty-two joined with eight
joined with one for a total of forty-one (thirty-two joined
with eight is forty or the eighth consecutive number after
thirty-two by counting by ones: (1) thirty-three, (2)
thirty-four, (3) thirty-five, (4) thirty-six, (5)
thirty-seven, (6) thirty-eight, (7) thirty-nine, (8) forty,
and one jointed together with forty is the next consecutive
number after forty, fourty-one). Therefore 101001 is
interpreted as forty-one in WHOLE BINARY.
Now let's make a few more key observations about WHOLE
BINARY:
- A word consisting of all 1's is the largest number that
can be represented with that many letters. (e.g. 111 is the
largest three-letter word in WHOLE BINARY.) Also a
non-zero word consisting of EXACTLY one 1 (must be in the
leftmost column since all non-zero words must have a 1 in its
leftmost column) is the smallest number that can be
represented with that many letters. (e.g. 1000 is the
smallest non-zero four-letter word in WHOLE BINARY.)
- The more letters a WORD in WHOLE BINARY contains,
the LARGER the number it represents.
- A word consisting of all 1's is ONE LESS than the word
containing ONE MORE LETTER than it and containing EXACTLY ONE
1 (in the leftmost column). (e.g. 111 is ONE LESS than 1000
in WHOLE BINARY.)
The reasons these properties hold true are as follows:
- All strings/words in WHOLE BINARY consist solely of
the letters 0 and 1. A 0 represents the absence of a package
and 1 represents the presence of a package, and packages only
increase the number. Therefore, a word consisting of all 1's
is the largest number that can be represented with that many
letters. Similarly, other than 0, every word in WHOLE
BINARY must contain at least one 1 (the LEFTMOST or
LEADING letter) so that a word consisting of EXACTLY one 1 is
the smallest non-zero number that can be represented with that
many letters.
- Recall the assembly line diagram in the previous section.
Packages roll on the conveyor belt from right to left so once
a column receives one, it will only give it up if it receives
another one. However, then it tapes the two packages together
and gives it to its closest neighbor on its LEFT. Its
closest neighbor will then either receive it and update its
column number to 1 to represent that it contains a package, or
if it already contains a package, then it will tape the two
packages and give it to its closest neighbor on the
LEFT. Eventually there will be a column that is in
possession of no packages (empty or contain a 0) so that it'll
receive a package and update its column to 1 to represent that
it is now in possession of a package. Since each column gives
packages to columns to the LEFT of it, the column that
eventually ends up having a 1 will be to the LEFT of
the first column giving up its package. Therefore, by
increasing a number, we will always wind up with a number with
AT LEAST AS MANY LETTERS as the original one.
Consequently, the more letters a WORD in WHOLE BINARY
contains, the LARGER the number it represents.
- A couple of ways to understand the reasoning behind this
third observation are as follows:
- We know that all words with EXACTLY ONE 1 must have the 1
appear in the leftmost column since all non-zero words in
WHOLE BINARY must have a 1 there. Then think about the
assembly line and the diagram in the previous tutorial to see
what happens when we increase a number represented with all
1's in WHOLE BINARY by ONE.
- Since a word consisting of all 1's is the LARGEST number
that can be represented with that many letters, a word
consisting of EXACTLY ONE 1 is the SMALLEST number that can be
represented with that many letters, LONGER words represent
LARGER numbers, and numbers are increased by ONE each time in
the assembly line, the LARGEST NUMBER we can represent with
ONE LESS letter (a string/word of all 1's in WHOLE
BINARY) MUST BE ONE LESS than the SMALLEST number WITH ONE
MORE letter (a string/word in WHOLE BINARY with 1 in
its leftmost column and 0 everywhere else) in WHOLE
BINARY.
Example: What number does 1111111 represent in WHOLE
BINARY? Again we can use our table, but this time let's
use the observation above to figure out the answer quickly.
| WHOLE BINARY COLUMN PLACE
NAMES |
| one thousand twenty-fours |
five hundred twelves |
two hundred fifty-sixes |
one hundred twenty-eights |
sixty-fours |
thirty-twos |
sixteens |
eights |
fours |
twos |
ones |
| |
|
|
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
| |
|
|
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
From the table, we have that the (smallest) eight-letter
word in WHOLE BINARY containing EXACTLY ONE 1
corresponds to the number one hundred twenty-eight given the
natural interpretation. Now since 1111111 is the (largest)
seven-letter word consisting of all 1's, we know by the above
observation that it must be ONE LESS than one-hundred
twenty-eight or one hundred twenty-seven so that 1111111 is
one hundred twenty-seven in WHOLE BINARY.
Exercise 1.3.1: What are the numbers 100001, 11 and 110
in WHOLE BINARY? Do you see the purpose of 0's as place
holders?
Exercise 1.3.2: Refer to the table above. Instead of
using the observation, we could have interpreted 1111111 in
WHOLE BINARY by joining one sixty-four with one thirty-two
with one sixteen with one eight with one four with one two
with one one, and we would have still received the same answer
of one hundred twenty-seven. Why is this true?
Representation of Numbers (Part 4)
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©2006 Jason Schanker