核心提示： 北师大版五年级上册数学《总复习》13、12.7+12.5÷5=12.7+2.5=15.2
5.01-1.9+4.99=5.01+4.99-1.9=8.1
0.4x99+0.4=0.4x99+0.4x1=0.4x(99+1)=0.4x100=40
3.6x4-2.5=14
北师大版五年级上册数学《总复习》
13、
12.7+12.5÷5
=12.7+2.5
=15.2
5.01-1.9+4.99
=5.01+4.99-1.9
=8.1
0.4x99+0.4
=0.4x99+0.4x1
=0.4x(99+1)
=0.4x100
=40
3.6x4-2.5
=14.4-2.5
=11.9
0.65x6.4-0.65x5.4
=0.65x(6.4-5.4)
=0.65x1
=0.65
78÷0.25÷0.4
=78÷(0.25x0.4)
=78÷0.1
=780