Bài giảng de thi hoc sinh gioi khỏi tháng 1 mon toan 2011

Đề thi học sinh giỏi khối 3 Tháng 1năm 2011
Môn thi : Toán
(Thời gian 60 phút )
Bài 1. Tính nhanh giá trị biểu thức :
a , 2+ 4 + 6 + 8 +....................+ 36 +38 +40 .
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b, 34 x 5 +3 x34 +68
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c, 121 +123 +125 +127 +129 +131 +133 +135 +137
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Bài 2. Tìm X:
a, X +(X +1 ) +(X +2 ) + ( X +3 ) +( X +4 ) = 110
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b, 98 : X =9 (dư 8 )

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.c, ( X: 5) -547 = 435 :5
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Bài 3. Tìm một số, biết rằng nếu lấy số đó nhân với 8 rồi cộng với chính nó thì
được 792 .
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Bài 4.Hiệu hai số bằng 818 .Nếu xoá chữ số 8 tận cùng bên phải số lớn thì được số
bé .Tìm tổng của hai số đó ?
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Bài 5.Một cửa hàng bán được 227 kg gạo nếp và gạo tẻ .Nếu cửa hàng bán
thêm 13 kg gạo tẻ thì số gạo tẻ gấp đôi số gạo nếp .Tính số gạo tẻ ,gạo nếp
cửa hàng bán được bao nhiêu kg?
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.Bài 7.Thương hai số là 108 .Nếu giảm số bị chia 9 lần ,giảm số chia 6 lần thì
thương mới bằng bao nhiêu ?
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