①88.2÷9=9.8 ②88.83÷9=9.87 ③88.884÷9=9.876
④88.8885÷9= ⑤88.88886÷9= ⑥88.888887÷9=
(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)
+ + =(1- )+( - )+( - )
+ + + + =
99×0.77=76.23
999×0.777=776.223
9999×0.7777=7776.2223
那么:999999×0.777777=
6.6×6.9=45.54
6.66×66.9=445.554
6.666×666.9=
6.6666×6666.9=
6.66666×66666.9=
4.2÷0.7=6
44.22÷6.7=6.6
444.222÷66.7=6.66
4444.2222÷666.7=
=
0,3,8,15,24,…,。
…
102-=,
n2-=。
1×3+1=22
2×4+1=32
3×5+1=42
……
×+1=20222
n×(n+2)+1=2(n为自然数)