①17.8×31.2÷5.2
②1.6-1.2+37.8
③47.9--
④68×99
12÷0.9≈
12÷0.03=
25×40%=
2.4-2.4×0.5=
8×5÷8×5=
1- = + = × × =
60×30%= 0÷ = + - - =
1.92÷0.04= 8.3-2.53= 5.7×3.2-2.2×5.7=
700+280= 0.5×12= 15÷10= 14÷0.2=
3.7+0= 9×80%= 8﹣2.6= +=
=