两道小学数学题（超级简单）

Question

1.用简便算法计算
393×99 67×39+32×39+39

Answer 1

393×（100-1）=39300-393
67×39+32×39+39=(67+32+1)×39=3900

Answer 2

393×99
=393*(100-1)
=39300-393
=38907

67×39+32×39+39
=39*(67+32+1)
=39*100
=3900本回答被提问者采纳

Answer 3

393×(100-1)
=39300-393
=38907

(67+32+1)×39
=100×39
=3900

Answer 4

393*（400-1）＝38907

39*（67+32+1）＝3900