And the stones were twelve according to the names of the children of Israel, graven according to their names like seals, each according to his own name for the twelve tribes.
WEB
Exodus 36:21
Ten cubits was the length of a board, and a cubit and a half the width of each board.
Parallel Translations
And the stones were twelve according to the names of the children of Israel, graven according to their names like seals, each according to his own name for the twelve tribes.
The length of a board was ten cubits, and the breadth of a board one cubit and a half.