180÷6= += ÷3= ×=
6﹣3.3= 2.2+3.57= ﹣= 39.5÷8≈(估算)
0.125×4= ×12= := 8×÷8×=
32.8+17.2= 902﹣457= 6×1.2=
0.32÷0.4= -= +=