- = - = - = + = + =
1- = + = - = + = - =
53=
2.4×5÷2.4×5=
33=
12÷0.3=
2.1×0.1=
0.6+4.44=
=
5÷9= 0.25×8= 23=
35既是2的倍数,又是5的倍数;42是3的倍数。