An interesting suggestion from Bob Graf reads:
The brass tub in Solomon's temple was a thick-sided vessel, and the measurement of ten cubits referred to the outer diameter, while the measurement of thirty cubits referred to the inner circumference. The thickness of the annulus was recorded as a hand-breadth. If one considers a hand breadth to be 4 inches, and uses a figure of 17.75 for a cubit, the value of p in the equation:
((10 - 30/p)/2)*17.75 = 4
is p = 355/113 .

I don't think the Hebrews calculated the values recorded, merely observed them. The true value of pi would give slightly different values for a hand-breadth and a cubit. I think this fact is more interesting than the improper imputation of 3 as the 'Biblical' value of pi.

Comment by: Bob Graf, 29th October 1996.

We note that the value 355/113 as an approximation for pi was first noted by Zu Chongzhi (430-501 AD)