- 计算:1992+12-113+212-313+412-513+…+199012-199113=______.
- 9+99+999+9999+99999+999999=______.
- (2000-1)+(1999-2)+(1998-3)+…+(1002-999)+(1001-1000)
- (4+8+12+16+…+1000)-(5+10+15+20+…+1000)
- 1998+1997-1996-1995+1994+1993-1992-1991+…+198+197-196-195.
- 计算:100+99+98-97-96+95+94+93-92-91+…+10+9+8-7-6+5+4+3-2-1=______.
- 2+4-6+8+10-12+14+16-18+…+1202+1204-1206+1208+1210-1212.
- ①2003+2002-2001-2000+1999+1998-1997-1996+…+7+6-5-4+3+2-1②95×125+125×14-25×5③99999×7+11111×37④0.125×0.25×0.5×64⑤13.5×9...
- 你能用几种方法来计算?1+3+5+7+…+93+95+97+99=
- 3.50707…可以记作______,保留两位小数是______.
- 计算:121+124+123+121+1221000+999-998-997+996+995-994-993+…+108+107-106-105+104+103-102-101.
- 计算:53-50+47-44+41-38…-14+11-8+5-2=______.
- 613+614+615+616+617+618+619=______×______=______.
- 497+498+499+500+501+502+503=______×______.
- 131+132+130+129.