Step 1:
The first step to converting 78260521889.145 to a fraction is to re-write 78260521889.145 in the form p/q where p and q are both positive integers. To start with, 78260521889.145 can be written as simply 78260521889.145/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 78260521889.145, which in this case is 3. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 78260521889.145/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 78260521889.145/1 each by 1000:
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 78260521889.145 as a fraction:
78260521889/1 / 1