1,计算:1+0.99-0.98-0.97+0.96+0.95-0.94-0.93+…+0.04+0.03-0.02-0.01 1+0.99-0.98-0.97+0.96+0.95-0.94-0.93+…+0.04+0.03-0.02-0.01
=1+(0.99-0.98-0.97+0.96)+(0.95-0.94-0.93+0.92)+…+(0.03-0.02-0.01)
=1,
2,计算1-2+3-4+5-6+...-2000+2001=
(1-2)+(3-4)+...+(1999-2000)+2001=-1*1000+2001=1001 3,计算:9.996+29.98+169.9+3999.5 9.996+29.98+169.9+3999.5
=10+30+170+4000-(0.004+0.02+0.1+0.5) =4210-0.624 =4209.376
4,计算:0.1+0.2+0.3+…+0.8+0.9+0.10+0.11+0.12+…+0.19+0.20 0.1+0.2+0.3+…+0.8+0.9+0.10+0.11+0.12+…+0.19+0.20 =(0.1+0.9)×9÷2+(0.10+0.20)×11÷2 =4.5+1.65
=6.15
5,计算:9.9×9.9+1.99 9.9×9.9+1.99
=99×0.99+0.99+1 =(99+1)×0.99+1 =100
6,计算2.437×36.54+243.7×0.6346 7,计算:1.1×1.2×1.3×1.4×1.5 1.1×1.2×1.3×1.4×1.5
=1.1×1.3×0.7×2×1.2×1.5 =1.001×3.6
=3.6036
8,计算:9.996+29.98+169.9+3999.5 9.996+29.98+169.9+3999.5
=10+30+170+4000-(0.004+0.02+0.1+0.5) =4210-0.624 =4209.376
1.5.467+3.814+7.533+4.186 2.6.25×1.25×6.4
3.3.997+19.96+1.9998+199.7
4.0.1+0.3+…+0.9+0.11+0.13+0.15+…+0.97+0.99 5.199.9×19.98-199.8×19.97
6.23.75×3.987+6.013×92.07+6.832×39.87 7.20042005×20052004-20042004×20052005
8.(1+0.12+0.23)×(0.12+0.23+0.34)-(1+0.12+0.23+0.34)×(0.12+0.23) 9.6.734-1.536+3.266-4.464 10.0.8÷0.125
11.89.1+90.3+88.6+92.1+88.9+90.8 12.4.83×0.59+0.41×1.59-0.324×5.9 13.37.5×21.5×0.112+35.5×12.5×0.112
14,20.36-7.98-5.02-4.36 117.8÷2.3-4.88÷023 9.56×4.18-7.34×4.18-0.26×4.18
15,

