I’am going to show you how to estimate the scale number of 39. Figure out how close you can get to 39, it would be 6*6=36 and 7*7=49. Find the middle of 36 and 49 it is 42. The answer is 6.2 why it is not 6.1 because it is to close, and 6.3 is little to far. The answer is 6.2.