Step 1:
The first step to converting 221218.9850428 to a fraction is to re-write 221218.9850428 in the form p/q where p and q are both positive integers. To start with, 221218.9850428 can be written as simply 221218.9850428/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 221218.9850428, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 221218.9850428/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 221218.9850428/1 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 221218.9850428 as a fraction:
221219/1 / 1