The library can be used since .NET 4.0 or .NET Standard 1.3. It's also CLS compliant to allow use in VB.NET. The Rationals library is an alternative to BigRational found in BCL. Its implementation is ...

The method to divide fractions is to keep the first fraction the same, turn the divide sign into a multiply and turn the second fraction upside down. This is known as multiplying by the reciprocal.