Calculate the decimal number for each fraction and identify the ascending numerical order of the decimal number

5/8 , 1/4, 3/8 ,2/3 6/7

To calculate the decimal number for each fraction, divide the numerator by the denominator:

5/8 = 0.625
1/4 = 0.25
3/8 = 0.375
2/3 = 0.666...
6/7 = 0.857...

Now, to identify the ascending numerical order of the decimal numbers:

0.25, 0.375, 0.625, 0.666..., 0.857...

So, the ascending numerical order of the decimal numbers is: 0.25, 0.375, 0.625, 0.666..., 0.857...