问题
解答题
先估后算.
例:2.96×32=?
估:3×300=900
算:2.96×32=94.72
(1)8.29×9=
(2)18.3×22=
(3)0.83×19=
答案
(1)8.29×9,
估:8×9=72;
算:8.29×9=74.61;
(2)18.3×22,
18×20=360,
18.2×22=400.4;
(3)0.83×19,
1×19=19;
0.83×19=15.77.
先估后算.
例:2.96×32=?
估:3×300=900
算:2.96×32=94.72
(1)8.29×9=
(2)18.3×22=
(3)0.83×19=
(1)8.29×9,
估:8×9=72;
算:8.29×9=74.61;
(2)18.3×22,
18×20=360,
18.2×22=400.4;
(3)0.83×19,
1×19=19;
0.83×19=15.77.