=ROUNDDOWN(A1,0)+IF((A1-ROUNDDOWN(A1,0))>=0.875,1,IF((A1-ROUNDDOWN(A1,0))>=0.625,0.75,IF((A1-ROUNDDOWN(A1,0))>=0.375,0.5,IF((A1-ROUNDDOWN(A1,0))>=0.125,0.25,0))))