小學(xué)二年級數(shù)學(xué)口算題大全:整十數(shù)加減法

400 + 900 = 100 + 600 = 900 + 800 =
     200 + 400 = 200 + 300 = 700 + 400 =
     500 + 700 = 200 + 300 = 700 + 400 =
     600 + 400 = 200 + 700 = 300 + 500 =
     800 + 700 = 100 + 800 = 800 + 100 =
     900 + 700 = 900 + 300 = 200 + 200 =