① a×0.6 ② a÷0.6 ③ a×0.8 ④ a÷0.8
1.25×0.8= 0.01×0.1= 2.5×4=
3.5×3= 0×3.78= 1.2+0.04=
0.5×1.2= 16÷5= 25÷1000=
x
5
12
y
30
a