10-12 is the same as 1 x 10-12
Since the exponent is negative you move the decimal 12 places to the left.
If it had been 1012 you would move the decimal 12 places to the right
1012 = 1 x 1012 = 1,000,000,000,000
You can just write 2.729 * 0.000000000001
