Charlie's steps for 3 kilometers is 5350 x 2 = <<5350*2=10700>>10700 steps were made when he run twice the field.
Since he has run half of the field 5350 / 2 = <<5350/2=2675>>2675 steps were made when he runs half of the 3-kilometer field.
Therefore, Charlie was able to make 10700 + 2675 = <<10700+2675=13375>>13375 steps for the 2 and a half run around the field.
#### 13375