Until 1971 the currency in the United Kingdom of Britain was duodecimal, called **pounds, shillings and pence**.

This old system of currency, known as pounds, shillings and pence or lsd, dated back to Roman times when a pound of silver was divided into 240 pence, or denarius, which is where the ‘d’ in ‘lsd’ comes from. (lsd: librum, solidus, denarius). see historic-uk.com

There were 12 pence in a shilling and 20 shillings in a pound, that is 240 pennies. The change to a decimal (100) pence in a pound caused a lot of inflation during the changeover due to price opportunism, then part lasting recession. In British heads **the skill of giving and taking change in a duodecimal arithmetic** was soon lost. In the late 70’s my mother, when visiting the US, was amusingly referencing “old money”, alongside the exchange rate between a decimal pound and the decimal dollar, just as Greeks had problems with the Euro.

## History of Decimal Measures

Napoleon sought to “rationalize” all the ancient weights and measures of France culminating in the decimal units within modern science, firstly CGS (Centimeter-Gram-Seconds) and then MKS (Meters-Kilogram-Seconds).

The Meter exemplifies the situation: it contains 100 centimeters and 1000 millimeters whereas the root foot for the worldwide and only ancient metrology is that called English which has 12 inches (each a “thumb” in French) and each inch halves, quarters, eighths and sixteenths of an inch, but also 10ths etc., that is a duodecimal system and decimal notation as with 12 = 10 +2.

The metrology of the ancient world had no need for decimalization since it had been formed to employ all the integer numbers, using fractions of a foot – fractions being a **combined multiplication (numerator) and division (denominator) operation**. That is, t**here was no base-10 decimal notation** when metrology was developed and one can suggest that decimalization was created in the wake of treasuries, mints and central banks.

However, decimal notation emerged much earlier with the alphabetic form of writing languages down. Cuneiform had used compound sounds (called **syllables **such as “no”) but the new Phoenician alphabets notated the consonants and vowels of specific languages, now called **phonemes **of sound (for exampple, the phonemes “n” and “o”). This reduces the number of symbols needed to notate speech, and in turn these symbols could then have a decimal function and **words could also be numbers**, in a code called Gematria:

Gematriais the practice of assigning a numerical value to a name, word or phrase by reading it as a number, or sometimes by using an alphanumerical cipher. Wikipedia on Gematria.

As the name implies, Alpha equals 1, Beta =2, D = 4, J = 10, etc.. Words could then encode a number, as in the Bible where Adam equals the three letters A.D.M whose numerical values in Hebrew/ Aramaic (1.4.40): when added up they “mean” 45. The later letters were values in tens and hundreds so that decimalization probably goes back to the 1st millennium BCE.

*Figure 1 Numeric equivalence of Hebrew Alphabet*

We are therefore needing to go earlier than the decimal base-10 system or indeed the use of any base at all, to see into the world of the megalithic astronomer and different relationships to numbers.

This previous world which gave birth to a type of math that is not arithmetical but instead used the factors within integers and rational fractions, initially through measured geometrical proportionality but then through sets of measures all rational fractions of the common foot.

## Prehistory: Non-Decimal Measures

The earliest number encountered by early astronomers would have been (when they counted) the **twelve lunar months** within a year. The properties of the number twelve are generally taken to come from its factors (such as 4 x 3), it Platonic solid (the duodecahedron) – see next section. There were no twelve hours in half a day. We will the take a deeper approach, of visualizing the set of numbers within twelve, as {1,2,3,4,5,6,7,8,9,10,11,12}

*Factors *within Twelve

Twelve does not contain is the prime number 5 nor any higher prime factor. However, in counting to 12, there are two factors containing 5, namely 5 and 10. And there are, of course, the prime numbers and their ennumerated multiples, such as, for 7, {14, 21, 28, 35, 42, 49, 56, …}. This means the number field is made up of empty slots into which the number one greater than the preceding number must then be a prime number. And any prime number can then be doubled, tripled, etc., to become enumerated itself. That is, which we call prime numbers are those that happen to have no preceding number of which it is a multiple of any (previously arisen) number.

*Numbers *Within Twelve

Twelve does not contain is the prime number 5 nor any higher prime factor. However, in counting to 12, there are two factors containing 5, namely 5 and 10. And there are, of course, the prime numbers and their ennumerated multiples, such as, for 7, {14, 21, 28, 35, 42, 49, 56, …}. This means the number field is made up of empty slots into which the number one greater than the preceding number must then be a prime number. And any prime number can then be doubled, tripled, etc., to become enumerated itself. That is, which we call prime numbers are those that happen to have no preceding number of which it is a multiple of any (previously arisen) number.

*Figure 2 The inner structure of Twelve*

Figure of (top) the first twelve numbers, four of which divide by three, making the even numbers (orange) alternate with the odd numbers in serpentine fashion. Numbers dividing by 5 then alternate down then up, every two threes. (bottom) the color keys used. (One could show primes with italics)

In a following post, the consequences of this inner structure reveal Twelve’s cellular structure within the number field.