0.25+2.25(二又四分之一)+3.75-1.5(1又二分之一)-3.75(3又四分之三)=1
原式=1/4+(2+1/4)+(3+3/4)-(1+2/4)-(3+3/4) =1/4+2+1/4+3+3/4-1-2/4-3-3/4 =(2+3-1-3)+(1/4+1/4+3/4-2/4-3/4) =1+0=1
