This also explains why we arrived at 9.8 instead of at 10 on the Egyptian map. If we consider 0.1 to be needed for the staff (or flag, neter) at the border, then we reach 9.8 + 0.1 + 0.1 = 10.

The figure '1' is evidently a flag.

In the calendar of the day there are 6 double-hours = 12 hours for the day. In the year there are 6 double-months = 12 months for a year.

At six equidistant points around the perimeter double measuring staffs are planted, back-to-back (Janus, Takurua).

Even the sky has been measured and mapped in this way. "Precession through two zodiacal constellations, or 60 degrees along the ecliptic, takes 4320 years."

Strangely, I noticed the other day that the distance to the Moon is (on the average) 60 times the diameter of the Earth.