The oral world of early numeracy was rather like number theory, where numbers can be observed as being related to the geometries of square, triangle and hexagon. The Islamic world of the Sufis appears to have continued this form of numeracy.

A recent book about possible Platonic numeracy in the Quran, Plato and the Quran, suggests the numbers 3 to 9 were stated as a puzzle inviting both the addition and multiplication for seven consecutive numbers, to generate two significant numbers, 33 and 20160, where 33 reminds us of the solar hero period of 33 years and 20160 is twice 10080, the diameter of the equal perimeter model of the Earth and the Moon.

Many centuries later, an early poem of Sufi master Ahmad Yasavi, in present day Khazakhstan, expressed a similar additive formula; that one should add the numbers 4 to 8 together and, when done, this generates the number 22. Twenty two was important in the ancient world and was seen to form the geometry of the equal perimeter square side 11 and circle diameter 14, which, can represent the relative sizes of the Earth and Moon. The geometry is a manifestation of a useful approximation to pi, as 22/7 = 3 + 1/7 or 3.142857, instead of the transcendent number 3.14159 … .

If one looks at the sequence, there are four numbers starting with four and so part of 22 is here 4 x 4 = 16, a square number. In addition there are the added ones of enumeration.: 4 + 1 = 5 + 1 = 6 + 1 = 7. These add up to 1 + 2 +3 = 6, a triangular number which one famously sees in the Tetractys of 1 + 2 + 3 + 4, then usually expanding downwards from 1, and this then adding to 6 + 4 = 10.

The lesser triangle of 6 can sit on top of the square of 16 to equal 22 while looking like a house roof for the square. The whole structure is seven units tall and I am looking at calling this a house number, but perhaps it is known somewhere in the literature – please let me know.

1. The first house number must be 5, a single 1 above 4 = 2 x 2.
2. The second house must be 12, a triangle of 3 above 9 = 3 x 3.
3. The fourth is 22.
4. The fifth is 35, a triangle of 10 above the square of 25 = 5 x 5.
5. The sixth is 51 , a triangle of 15 above the square of 36 = 6 x 6.

In each case, the triangle’s bottom row can be seen to share the top row of the house’s square and the triangular roof is most simply equilateral.

I wish happy celebration to my worldwide visitors, between the solstice and new calendar year; inviting you to see this “house number” as a “room” with a celestial “roof”.