The Egyptian Cubit

I have decided to continue my "researches" here where postings are less restricted.

We can compare various feet which have been used and the nsec,

1 pes (Roman foot) = 296 mm
1 pous (Ionian foot) = 296 mm
1 English foot = 305 mm
1 Egyptian bd = 300 mm

1 nsec = 300 mm

The Egyptian bd is 4 "hand breadths" of 4 fingers and there are 7 hand breadths to a cubit so the bd was 16 fingers and the cubit was 28 fingers. If the bd was the primary unit the cubit would be 7/4 of it. Is there any significance to this?

7 = 1 + 2 + 4 → 7/4 = 1 + 1/2 + 1/4

These are Eye of Horus fractions and the representation of integers as a sum of powers of 2 was used for multiplication.

The Egyptians made the conversion 2/7 → 1/4 +1/28 so 4/7 = 1/2 + 1/14 could also be easily represented and calculations involving 4/7 would not pose any difficulty.

Eye of Horus fractions would have been of greater significance to the Egyptians. 7/4 was more fundamental.