Step 1:
The first step to converting 1690.642 to a fraction is to re-write 1690.642 in the form p/q where p and q are both positive integers. To start with, 1690.642 can be written as simply 1690.642/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 1690.642, which in this case is 3. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 1690.642/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 1690.642/1 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 1690.642 as a fraction:
23669/14 / 1