数学简便运算.(用脱式计算)

8.4÷1.4÷3
=8.4÷(1.4*3 )
=8.4÷4.2
=5
0.84÷2.5
=0.84÷10*4
=0.084*4
=3.36
0.99÷15
=0.99÷3÷5
=0.33÷5
=0.33÷10*2
=0.033*2
=0.066
0.36×102+0.28
=0.36×(100+2)+0.28
=0.36×100+0.36×2+0.28
=36+(0.72+0.28)
=37
8.2×0.99+0.8×0.99+0.99
=0.99×(8.2+0.8+1)
=0.99×10
=9.9