$o=sprintf "%10.4e",$o; print "$o\n"; #### 1.4100e-03 1.9881e-06 2.8032e-09 3.9525e-12 5.5730e-15 7.8579e-18 1.1080e-20 1.5623e-23 2.2028e-26 3.1059e-29 4.3793e-32 #### 0.00141 0.0000019881 0.0000000028032 0.0000000000039525 0.000000000000005573 0.0000000000000000078579 0.00000000000000000001108 0.000000000000000000000015623 0.000000000000000000000000022028 0.000000000000000000000000000031059 0.000000000000000000000000000000043793