解1：
0.42/35
=0.42÷35
=0.42÷(7×5)
=0.42÷7÷5
=0.06÷5
=(0.06×2)÷(5×2)
=0.12÷10
=0.012
解2：
0.42/35
=42/3500
=(6×7)/(500×7)
=6/500
=(6×2)/(500×2)
=12/1000
=0.012
÷
解1：
0.42/35
=0.42÷35
=0.42÷(7×5)
=0.42÷7÷5
=0.06÷5
=(0.06×2)÷(5×2)
=0.12÷10
=0.012
解2：
0.42/35
=42/3500
=(6×7)/(500×7)
=6/500
=(6×2)/(500×2)
=12/1000
=0.012
÷