信息窗3练习设计第1题答案
2.5×1.9×4=4×2.5×1.9
3.8×2.7+6.2×2.7=(3.8+6.2)×2.7
2.97×0.5×0.2=2.97×(0.5×0.2)
32×10.1=32×(10+0.1)=32×10+32×0.1
信息窗3练习设计第2题答案
(1)0.12×0.38≈0.05 0.75×2.07≈1.55
(2)1.3×3.4≈4.4 0.09×1.7≈0.2
信息窗3练习设计第3题答案
+;-;×
信息窗3练习设计第4题答案
信息窗3练习设计第5题答案
4.2×5.5×1.2
=23.1×1.2
=27.72
4.6×1.45-1.08
=6.67-1.08
=5.59
2.95×0.2×3.4
=0.59×3.4
=3.9
信息窗3练习设计第6题答案
0.25×4.78×4
=(0.25×4)×4.78 3.4×9+3.4
=3.4×(9+1)
=3.4×10
=34
2.7×4.3+2.7×5.7
=2.7×(4.3+5.7)
=2.7×10
=27
1.25×11×0.8
=(1.25×0.8)×11
=1×11
=11
4.6×102
=4.6×(100+2)
=4.6×100+4.6×2
=460+9.2
=469.2