1.9-0.89= 0.72= a×a= 8x-7x=
0.99+1.8= 0.012÷0.4= 0.5×0.29= 4+2.5-4+2.5=
①1.56-0.45+0.55
②3.56-0.2+6.44-4.8
③3.2+9.6÷0.32
④3.5×5.2+0.35×48
⑤1.25×0.32×25
⑥4.75×[60÷(3.24-3.04)]