- 2009-2008+2007-2006+2005-2004+…+3-2+1=______.
- 计算:2004+2005+2006+2007+2008+2009+2010=______.
- 计算(1+3+5+…+2011)-(2+4+6+…+2010)=______.
- 9+99+999+9999.
- 151+148+155+147+154+149+155+152+145.
- 计算:13+73+132+145+255+274+326+368+427=______.
- 计算:24-23+22-21+…+4-3+2-1=______.
- (1+3+5+…+19)-(2+4+6+…+18)=______.
- (7+9+11+13+…+37)-(9+11+13+15+…+35)=______.
- 计算9999+999+99+9+8=______.
- 19+199+1999+19999+199999.
- 计算:1+2+3+4+5+6+7+8+9+10.
- 计算(1)6000-1-3-5-…-97-99(2)137×125×5×8×20.
- 简便计算:98+97-96-95+94+93-92-91+90+89…-4-3+2+1.
- 计算:1999.9+199.9+19.9+1.9=______.