6.6×3.4=22.44
6.66×33.4= 222.444
6.666×333.4=
6.66666×33333.4=
99.99×2=199.98
99.99×3=299.97
99.99×4=
99.99×7=
1×3+1=22
2×4+1=32
3×5+1=42
……
×+1=20222
n×(n+2)+1=2(n为自然数)
①1.25×(30.1﹣24.91÷4.7)
②[ ﹣( ﹣ )]÷
③15.6×13.1﹣15.6﹣15.6×2.1
④2 ×23.4+11.1×57.6+6.54×28
⑤1234+2341+3412+4123
⑥ + + + + +