The Template:Convert/numdisp/frac1 formats a fraction (or mixed number) for positive values, with parameters as follows:

parameter 1 - blank, used by {Convert/numdisp/frac}
parameter 2 - the whole number portion (if any)
parameter 3 - numerator of fraction portion
parameter 4 - denominator of fraction portion

All 4 of the parameters are required, although {2} can have an empty/blank value.

{{convert/numdisp/frac1| |2000|12|50}} → Шаблон:Convert/numdisp/frac1
{{convert/numdisp/frac1| ||7|8}}            → Шаблон:Convert/numdisp/frac1

For negative values, the related Template:Convert/numdisp/frac-1 is used instead, to format data with unicode &minus.