Question

脫式計算，能簡便的簡便計算
9.08-2.12-1.88
4.02-3.5+0.98
0.25×17.3×0.4
2.71×6.5+3.5×2.71
0.79×34+7.9×5.6+7.9．

Answer 1

（1）9.08-2.12-1.88
=9.08-（2.12+1.88）
=9.08-4
=5.08

（2）4.02-3.5+0.98
=4.02+0.98-3.5
=5-3.5
=1.5

（3）0.25×17.3×0.4
=0.25×0.4×17.3
=0.1×17.3
=1.73

（4）2.71×6.5+3.5×2.71
=2.71×（6.5+3.5）
=2.71×10
=27.1

（5）0.79×34+7.9×5.6+7.9
=7.9×3.4+7.9×5.6+7.9×1
=7.9×（3.4+5.6+1）
=7.9×10
=79．