Bài 1: Đặt tính rồi tính:
142,5 : 75 | 36 : 3,2 | 23 : 2,4 | 705 : 45 |
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12,75 : 57 | 9: 12,5 | 336: 45 | 1649 : 4,85 |
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Bài 2: Điền số thích hợp:
9,4km2 = .............................................m2 2,82 m2 = .............................................cm2 9, 75hm2 = .............................................m2 5,34 m = ...............................................cm 3, 6dam =.............................................dm | 235,2m2 = .............................................ha 520 m2 = .............................................dam2 112 m234cm2 = ......................................m2 35,6ha= ....................................km2 34567m2 = ..........................ha |
Bài 3: Một xe máy trong 2 giờ đầu, mỗi giờ chạy 35km ; trong 3 giờ sau, mỗi giờ chạy 32km. Hỏi trung bình mỗi giờ xe máy chạy bao nhiêu km ?
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Bài 4: Một người nuôi ong thu hoạch được 40l mật ong. Người đó muốn đổ số mật ong đó vào các chai, mỗi chai chứa 0,5l mật ong. Hỏi cần ít nhất bao nhiêu vỏ chai để đựng hết số mật ong đó.
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Bài 5: Biết rằng 0,75l sữa thì cân nặng 0,81kg. Hỏi 4,5 lít sữa thì cân nặng bao nhiêu kg?
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Bài 2 :
a) \(x.3,9+x.0,1=2,7\)
\(x.\left(3,9+0,1\right)=2,7\)
\(x.4=2,7\)
\(x=2,7:4\)
\(x=0,675\)
b) \(12,3:x-4,5:x=15\)
\(\left(12,3-4,5\right):x=15\)
\(7,8:x=15\)
\(x=7,8:15\)
\(x=0,52\)
Bài 3 :
Thương của số bé và số lớn cũng bằng 0,6 =>\(\dfrac{Bé}{Lớn}=\dfrac{6}{10}=\dfrac{3}{5}\)
Số bé : \(0,6:\left(3+5\right)\) x \(3=0,225\)
Số lớn : \(0,6-0,225=0,375\)