下面各题能简便的就简便方法计算.999.9+99.9+9.9+0.9 6.92-十一分之八-十一份之三+3.18 497-97×3+37(九分之一+六分之五-十八分之七)×36 九分之四×[0.75-(十六分之七-0.25)]1.32×八分之五+2.68÷1.6
问题描述:
下面各题能简便的就简便方法计算.999.9+99.9+9.9+0.9 6.92-十一分之八-十一份之三+3.18 497-97×3+37
(九分之一+六分之五-十八分之七)×36 九分之四×[0.75-(十六分之七-0.25)]
1.32×八分之五+2.68÷1.6
答
999.9+99.9+9.9+0.9
=1000-1+0.9+100-1+0.9+10-1+0.9+0.9
=1110-3+0.9×4
=1110-3+3.6
=1110.6
6.92-8/11-3/11+3.18
=6.92-(8/11+3/11)+3.18
=6.92+3.18-1
=10-1
=9
497-97×3+37
=400+97-97×3+37
=400+97×(1-3)+37
=400-97×2+37
=400-194+37
=206+37
=243
(九分之一+六分之五-十八分之七)×36
=4+30-14
=12
九分之四×[0.75-(十六分之七-0.25)]
=九分之四×[0.75-十六分之七+0.25]
=九分之四×[1-十六分之七]
=4/9×9/16
=1/4
1.32×5/8+2.68÷1.6
=1.32×5/8+2.68÷8/5
=1.32×5/8+2.68×5/8
=5/8×(1.32+2.68)
=5/8×4
=5/2
=2.5