Step 1:
The first step to converting 856123.6428639 to a fraction is to re-write 856123.6428639 in the form p/q where p and q are both positive integers. To start with, 856123.6428639 can be written as simply 856123.6428639/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 856123.6428639, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 856123.6428639/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 856123.6428639/1 each by 10000000:
Step 3:
Now the last step is to simplify the fraction (if possible) by finding similar factors and cancelling them out, which leads to the following answer for 856123.6428639 as a fraction:
856123/1 / 1