19.98×37-199.8×1.9+1998×0.82 888+32×0.125×0.25 7.8÷[32×(1-5/8)+3.6] 1/1×2+1/2×3+1/3×4+…+1/99×100.

问题描述:

19.98×37-199.8×1.9+1998×0.82 888+32×0.125×0.25
7.8÷[32×(1-
5
8
)+3.6]
1
1×2
+
1
2×3
+
1
3×4
+…+
1
99×100

(1)19.98×37-199.8×1.9+1998×0.82,=19.98×37-19.98×19+19.98×82,=19.98×(37-19+82),=19.98×100,=1998;(2)888+32×0.125×0.25,=888+(8×4)×0.125×0.25,=888+(8×0.125)×(4×0.25),=8...