7道简便计算、一道10分.( / ←此为分数线)1.1×2+2×3+3×4+……10×112.9999×2222+3333×33343.0.5×236×59/1194.238÷238又238/239 (带分数)5.125又1/20(带分数)÷416.6209/10013×10693/22869÷3337/106027.(1/2-1/3)+

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7道简便计算、一道10分.( / ←此为分数线)1.1×2+2×3+3×4+……10×112.9999×2222+3333×33343.0.5×236×59/1194.238÷238又238/239 (带分数)5.125又1/20(带分数)÷416.6209/10013×10693/22869÷3337/106027.(1/2-1/3)+
7道简便计算、一道10分.( / ←此为分数线)
1.1×2+2×3+3×4+……10×11
2.9999×2222+3333×3334
3.0.5×236×59/119
4.238÷238又238/239 (带分数)
5.125又1/20(带分数)÷41
6.6209/10013×10693/22869÷3337/10602
7.(1/2-1/3)+(1/4-1/5)+(1/7-1/10)+(1/14-1/15)+(1/28-1/30)

7道简便计算、一道10分.( / ←此为分数线)1.1×2+2×3+3×4+……10×112.9999×2222+3333×33343.0.5×236×59/1194.238÷238又238/239 (带分数)5.125又1/20(带分数)÷416.6209/10013×10693/22869÷3337/106027.(1/2-1/3)+
1.=2×(1+3)+4×(3+5)+6×(5+7)+8×(7+9)+10×(9+11)
=2×2×2+2×4×4+2×6×6+2×8×8+2×10×10
=2×(4+16+36+64+100)
=2×220=440
2.=3333×6666+3333×3334
=3333×(6666+3334)
=33330000
3.=0.5×2×118×59÷119
=58.50420168.【请检查题目】
4.将式子倒过来:238又238/239÷238=1又1/239=240/239
所以原式=239/240
5.=(123+2又1/20)÷41
=123÷41+41/20÷41
=3+1/20=3又1/20(或61/20)
6.=0.921173486【似乎没有简便算法,检查题目是否正确】
7.=(1/2+1/4)+(1/7+1/14+1/28)-1/3-1/5-1/15-1/30
=3/4+1/4-(10+6+2+1)/30
=11/30