①950÷50 =950÷(10×5) =950÷10÷5 =95÷5 =19 ②430÷20 =430÷(10×2) =430÷10÷2 =43÷2 =21.5 ③870÷80 =870÷(10×8) =870÷10÷8 =87÷8 =10 7 8