Step 1:
The first step to converting 637.645 to a fraction is to re-write 637.645 in the form p/q where p and q are both positive integers. To start with, 637.645 can be written as simply 637.645/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 637.645, which in this case is 3. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 637.645/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 637.645/1 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 637.645 as a fraction:
19767/31 / 1