A lot of currencies are sufficiently devalued that using k for thousands or even m for millions is incredibly common, such as with the Indonesian Rupiah. In fact, you'd be hard pressed to find anything that's not expressed in thousands of rupiahs. Therefore the conversion widget should support queries like "100k idr to euro". Bonus points for supporting the native superunits like rb (ribu) for thousands and jt (juta) for millions, e.g. "100 rb to euro" or just "100 rb idr to euro".
It would save lots of queries and time, as everyone familiar with the currency already instinctively uses these suffixes, only to be disappointed and having to replace them with a bunch of zeroes.
I expect this to work naturally like in any other app that considers suffixes and units, such as the following example from Qalculate 
