Is the Bible mathematically wrong in I Kings 7:23? If the diameter of the laver is 10 cubits, then shouldn't the circumference be 31 cubits?
"And he made the Sea of cast bronze, ten cubits from one brim to the other; it was completely round. Its height was five cubits, and a line of thirty cubits measured its circumference. Below its brim were ornamental buds encircling it all around, ten to a cubit, all the way around the Sea. The ornamental buds were cast in two rows when it was cast. It stood on twelve oxen: three looking toward the north, three looking toward the west, three looking toward the south, and three looking toward the east; the Sea was set upon them, and all their back parts pointed inward. It was a handbreadth thick; and its brim was shaped like the brim of a cup, like a lily blossom. It contained two thousand baths" (I Kings 7:23-26).
The laver was called "the Sea" because it was so big. To give you a rough idea of how big it was, it was 18 feet in diameter (probably bigger than your living room) and held 16,000 gallons of water.
First off, notice that the Sea had a brim; that is, there was a lip on the bowl that stuck out. There is one artist's rendering of what it might have looked like. When we are measuring the brim, was it from the outside edge or the inside edge? It does make a difference because the bowl was handspan (roughly four inches) thick. Was the circumference measuring from the inside or the outside of the bowl? Was the circumference measured at the very top or a bit further down, say at the waterline level?
Assuming the measurement for the diameter was outside to outside edge and the circumference was on the inside, we easily account for the missing 1.4 cubits that a 10 cubit bowl demands. A 10 cubit circumference would have a 9.55 cubit diameter. Assuming an 18-inch cubit, that gives us an 8.1-inch difference between the given diameter and the needed diameter for the circumference. That would mean the bowl's thickness was roughly 4 inches thick (a handspan).
Thus, there is no mathematical error. The only error is in assuming where the measurements were taken.