用简便方法计算6.5*7.7-7.6*2.1
用简便方法计算6.5*7.7-7.6*2.1
直接算比较简便。
6.5*7.7-7.6*2.1
=50.05-15.96
=50.05-16+0.04
=34.09
解析:(1)7.7和7.6接近,但6.5和2.1不能凑整,所以不能凑整简算。(2)对数乘数与数乘数相加减,可通过加减法结合律进行凑整简算,不能时直接按规则运算比较简便。
6.5*7.7-7.6*2.1用简算方法的式子
=7*(6.5*1.1-7.6*0.3)
=7*(7.15-2.18)
=7*(4.97+0.03-0.03)
=35-0.21
=34.79
能简便的用简便方法计算7.6+7.6×993.47+4.9+6.5
(1)7.6+7.6×99
=7.6×(1+99)
=7.6×100
=760
(2)3.47+4.9+6.53+5.1
=(3.47+6.53)+(4.9+5.1)
=10+10
=20
(3)0.25×4÷0.25×4
=0.25÷0.25×4×4
=1×4×4
=16
(4)21.12+1.4×5-6.02
=21.12+7-6.02
=28.12-6.02
=22.1
(5)0.6×(3.2-0.88)÷1.2
=0.6×2.32÷1.2
=1.392÷1.2
=1.16
用简便方法计算: 2.3+7.8+9.9*7.7+2.3*2.1=
=2.3+(10-0.1)*7.7+7.8+2.3*(2+0.1)
=2.3+77-0.77+7.8+4.6+0.23
=77+14.7-0.54
=77+13.16
=90.16
7.7×0.16÷7.7×12.5=??用简便方法计算
7.7÷7.7=1
0.16=0.08×8
8×12.5=100
0.08×100=8
7.7×0.16÷7.7×12.5=8
7.7×7+7.7+2×7.7 简便方法计算 125除以(50除以8) ,简便方法计算
7.7×7+7.7+2×7.7
=7.7×(7+1+2)
=7.7×10
=77
125÷(50÷8)
=125÷50×8
=125×8÷50
=1000÷50
=20
16.63 7.7 13.37用简便方法计算
37×44-37×13+37×76-37×7=37×(44-13+76-7)=37×100=3700
7.7×7+7.7+2×7.7 简便方法计算
7.7×7+7.7+2×7.7
=7.7×(7+1+2)
=7.7×10
=77
(7.6 1.2)x(7.6-1.2)用简便方法计算
7.6²-1.2²=57.76-1.44=56.32
用简便方法计算10.67加7.6
用简便方法计算10.67加7.6
=10.67+(8-0.4)
=10.67+8-0.4
=18.67-0.4
=18.27