小数的简便计算: 1:0.88×1.42+0.44×7.16 2: 21.49+52.37-0.4+5.51-11.37-6.6
问题描述:
小数的简便计算: 1:0.88×1.42+0.44×7.16 2: 21.49+52.37-0.4+5.51-11.37-6.6
答
1:0.88×1.42+0.44×7.16 =0.44×2×1.42+0.44×7.16=0.44×2.84+0.44×7.16=0.44×(2.84+7.16)=0.44×10=4.42:21.49+52.37-0.4+5.51-11.37-6.6=(21.49+5.51)+(52.37-11.37)-(0.4+6.6)=27+41-7=61