2÷14÷ = 0.1+9.9×0.1=
0.58+0.41=
12÷4
20÷20%=
84
1
3.14×52×4=
+6 -4 +10 -7 -6 +13 -9
5.25时=时分
6.05=605
9×9+19
=9×9+9+10
=9×(9+1)+10
=9×10+10
=(9+1)×10
=10×10
99×99+199