(10-1)÷0.9=
(200-2)÷0.9=
(3000-3)÷0.9=
(40000-4)÷0.9=
(500000-5)÷0.9=
(6000000-6)÷0.9=
(9999+9997+…+9001)-(1+3+…+999)
①88.2÷9=9.8 ②88.83÷9=9.87 ③88.884÷9=9.876
④88.8885÷9= ⑤88.88886÷9= ⑥88.888887÷9=
+ + =(1- )+( - )+( - )
+ + + + =
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 + + + + +