Step 1:
The first step to converting 1258.3428791808 to a fraction is to re-write 1258.3428791808 in the form p/q where p and q are both positive integers. To start with, 1258.3428791808 can be written as simply 1258.3428791808/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 1258.3428791808, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 1258.3428791808/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 1258.3428791808/1 each by 10000000000:
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 1258.3428791808 as a fraction:
40267/32 / 1