56+44= 0.9×0.6= 20﹣3.7= 8÷100= 2.5×3.5×4=
-= += 10÷= 15×= ×24+24=
+ = 50÷50%= = 3 -1.125=
1.9÷2.5÷0.4= ( )×18= = 1- =