Question

请用简便计算。

Answer 1

1 1.25x32x2.52 3.2 ×0.6＋2.8×0.63 0.39x1994 3.65x10.15 0.85x9.96 12.9x99+12.97 7.09x10.8-0.8x7.098 5.4x11-5.4 9 0.65x10110 2.5x26+2.5x6+8 不好意思只有这么多了，想不出来了，抱歉啊

Answer 2

如图

Answer 3

1/6 + 1/12 = 2/12 + 1/12 = 3/12 = 1/4
1/4 + 1/20 = 5/20 + 1/20 = 6/20 = 3/10
3/10 + 1/30 = 9/30 + 1/30 = 10/30 = 1/3
1/3 + 1/42 = 14/42 + 1/42 = 15/42 = 5/14
5/14 + 1/56 = 20/56 + 1/56 = 21/56 = 3/8
结果： 3/8

Answer 4

1/6+1/12+1/20+1/30+1/42+1/56
=1/（2×3）+1/（3×4）+1/(4×5）+1/（5×6）+1/（6×7）+1/（7×8）
=(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)
=1/2-1/8
=3/8

Answer 5

1/6+1/12+1/20+1/30+1/42+1/56
1/2*3+1/3*4+1/4*5+1/5*6+1/6*7+1/7*8
=1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8
=1/2-1/8
=4/8-1/8
=3/8