- (0.12+0.23+0.34)×(0.23+0.34+0.45)-(0.12+0.23+0.34+0.45)×(0.23+0.34)=______.
- 计算(22+42+62+82+…+1002)-(12+32+52+72+…+992)=______.
- (3456780-345678)÷(345678×3)=______.
- 计算99999×7+11111×37=______.
- 算式123456787654321×(1+2+3+4+5+6+7+8+7+6+5+4+3+2+1)的结果等于自然数______的平方.
- 计算2×4+4×6+6×8+…+98×100=______.
- (1)835×2.7+6.2×1.4+3.5×8.6(2)11-180+543×374543×375-363.
- 19931993×1993-19931992×1992-19931992.
- [2-(0.5+512×2.4)]÷120.
- 2020202×333-3030303×222=______.
- 1989×1999-1988×2000.
- 999×778+333×666.
- 987654321×1235-987654322×1234.
- 2007×20062006-2006×20072007=______.
- 82-72+62-52+42-32+22-12=______.