1200÷25 =(1200×4)÷(25×4) =4800÷100 =48 240÷12 =(240÷6)÷(12÷6) =40÷2 =20 120÷15 =(120×2)÷(15×2) =240÷30 =8 5400÷600 =(5400÷100)÷(600÷100) =54÷6 =9 2100÷25 =(2100×4)÷(25×4) =8400÷100 =84