2011年西师版小学数学三年级上册两三位数乘一位数练习题

估算下面各题（中间一步，以后熟练了，就可以不写出来。）

21×2≈ × = 32×2≈ × =

43×2≈ × = 54×2≈ × =

56×2≈ × =  57×2≈ × =

58×2≈ × =   59×2≈ × =

31×3≈ × = 42×3≈ × =

53×3≈ × = 64×3≈ × =

76×3≈ × = 87×3≈ × =

98×3≈ × = 99×3≈ × =

41×4≈ × = 52×4≈ × =

63×4≈ × = 74×4≈ × =

86×4≈ × = 97×4≈ × =

98×4≈ × = 99×4≈ × =

51×5≈ × = 62×5≈ × =

73×5≈ × = 84×5≈ × =

96×5≈ × = 97×5≈ × =

98×5≈ × = 99×5≈ × =

61×6≈ × = 62×6≈ × =

73×6≈ × = 74×6≈ × =

86×6≈ × = 97×6≈ × =

98×6≈ × = 99×6≈ × =

71×7≈ × = 82×7≈ × =

93×7≈ × = 94×7≈ × =

96×7≈ × = 97×7≈ × =

98×7≈ × = 99×7≈ × =

81×8≈ × = 82×8≈ × =

83×8≈ × = 84×8≈ × =

86×8≈ × = 87×8≈ × =