题目: 口算60×5=140×3=480÷60=630÷9=340+560=17×4=11×80=40×70=940-500=75÷15=326÷80≈103×49≈ 答案: 60×5=300140×3=420480÷60=8630÷9=70340+560=90017×4=6811×80=88040×70=2800940-500=44075÷15=5326÷80≈4103×49≈5000