Step 1:
The first step to converting 12105.612890253 to a fraction is to re-write 12105.612890253 in the form p/q where p and q are both positive integers. To start with, 12105.612890253 can be written as simply 12105.612890253/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 12105.612890253, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 12105.612890253/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 12105.612890253/1 each by 1000000000:
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 12105.612890253 as a fraction:
157373/13 / 1