1+2+3+4+5+6+7+...+999999999+1000000000=?(简便计算)
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/11 23:30:31
![1+2+3+4+5+6+7+...+999999999+1000000000=?(简便计算)](/uploads/image/z/4562454-30-4.jpg?t=1%2B2%2B3%2B4%2B5%2B6%2B7%2B...%2B999999999%2B1000000000%3D%3F%EF%BC%88%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%97%EF%BC%89)
1+2+3+4+5+6+7+...+999999999+1000000000=?(简便计算)
1+2+3+4+5+6+7+...+999999999+1000000000=?(简便计算)
1+2+3+4+5+6+7+...+999999999+1000000000=?(简便计算)
1+2+3+4+5+6+7+...+999999999+1000000000=1000000000*(1+1000000000)/2
1加999999999 然后逐一加 最后加上1000000000
1+2+3+4+5+6+7+...+999999999+1000000000=(1+1000000000)×1000000000÷2
1+2+3+4+5+6+7+...+999999999+1000000000
=1/2X1000000000X(1+1000000000)
=500000000500000000
(1+1000000000)+(2+999999999)+......+(500000000+500000001)=500000000500000000
1+2+3+4+5+6+7+...+999999999+1000000000
=(1+1000000000)*1000000000/2
=500000000500000000
再给你种简便方法:口决: 五加 5前5后少一零
1+2...10=55
1....100=5050
1...1000=500500
1.....10000=50005000
1...1000000000=500000000500000000
1+999999999=1000000000;
2+999999998=1000000000;
3+999999997=1000000000;
>>>>
5000000000+1000000000*4999999999