(1)900÷3=(9×100)÷3
=(9÷3)×100
=3×100
=300
(2)124÷4=(120+4)÷4
=120÷4+4÷4
=30+1
=31
(3)408÷4=(400+8)÷4
=400÷4+8÷4
=100+2
=102
(4)4÷124
=4×1/124
=1/31
(5)4÷408
=4×1/408
=1/102
(1)900÷3=(9×100)÷3
=(9÷3)×100
=3×100
=300
(2)124÷4=(120+4)÷4
=120÷4+4÷4
=30+1
=31
(3)408÷4=(400+8)÷4
=400÷4+8÷4
=100+2
=102
(4)4÷124
=4×1/124
=1/31
(5)4÷408
=4×1/408
=1/102