7/5*16*5/21簡便方法/為分數線

7/5*16*5/21簡便方法/為分數線


7/5*16*5/21
=(7X16X5)/(5X21)
=16X7/21X5/5
=16/3X1
=16/3
=5又1/3
(此題主要運用了乘法結合律進行簡便計算.)



(3又3分之1+0.75-2又8分之5)*3的簡便方法


(3又3分之1+0.75-2又8分之5)*3
=3*3+1/3*3+0.75*3-2.625*3
=9+1+2.25-7.875
=4.375
=4又3/8



用簡便方法計算:四分之一*6.12的2次方-4*1.04的2次方


四分之一*6.12的2次方-4*1.04的2次方
=(2分之1*6.12)²;-(2*1.04)²;
=3.06²;-2.08²;
=(3.06+2.08)(3.06-2.08)
=5.14*0.98
=5.14*(1-0.02)
=5.14- 0.1028
=5.0372



0.74*0.25+0.75簡便方法


0.74*0.25+0.75
=0.25(0.74+3)
=0.25*3.74
=0.935



0.64*0.25+0.75=的簡便方法


0.64*0.25+0.75
=0.16x4x0.25+0.75
=0.16+0.75
=0.91



4.75+3.59—0.59+4.25簡便方法


4.75+4.25+【3.59—0.59】=12



6.4-(2.75+2.4)-0.25的簡便方法


6.4-(2.75+2.4)-0.25
=6.4-2.75-2.4-0.25
=(6.4-2.4)-(2.75+0.25)
=4-3
=1



75*24用簡便方法


75×24
=75×(20+4)
=1500+300
=1800



簡便方法運算76+2.83+0.24


76+2.83+0.24
=76+3.07
=79.07.



3.6除以1.2+3.6除以2.4請問怎麼使用簡便方法(注意除數=2個被除數的和1.2+2.4=3.6哦)


3.6除以1.2+3.6除以2.4
=(1.2+1.2+1.2)÷1.2+(1.2+1.2+1.2)÷1.2÷2
=1+1+1+(1+1+1)÷2
=3+1.5
=4.5