The original doesn't say "10-15 meters" but ten to the power of negative fifteen meters, so his guess was off from the Bohr radius of 5.3E-11 in the other direc

The original doesn't say "10-15 meters" but ten to the power of negative fifteen meters, so his guess was off from the Bohr radius of 5.3E-11 in the other direction but by much fewer orders of magnitude than as rendered above.