0.7是7个 ,0.9是9个 ,所以0.7<0.9.
<<<
2.1+1.6=
3.4-1.2=
1.7+0.3=
5.8-2.8=
9.7-8.6=
5.1+4.8=
5-2.4=
3.7+6.3=
7.1+1.9=
8.4-7.3=
4.7+5.3=
7.5-2.5=