2.5×4= ×= ÷= ﹣0.25=
﹣= 1﹣﹣= 1÷20%= 80%×=
÷[(1+)×]
17×19×()
0.25×12.5×32
40×25%= 1.03×10= 3×45= 1÷10%= 2.8×=
1.57﹣0.85= 0.49÷0.7= 3.05+6.2= 0.6:0.75= kg:40g=