Giải bài 1 trang 29 - SGK Toán lớp 3
Tính rồi viết theo mẫu:
a) Mẫu: \(\bf \left. \begin{align} & \begin{matrix} \bf 12 \\ \bf 12 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\,\bf 0 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{6}{2} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \)
Viết: \(\bf 12 : 6 = 2\)
\(\left. \begin{align} & \begin{matrix} 20 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{5}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 15 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{3}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 24 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{4}{{}} \\ \end{matrix} \)
b) Mẫu: \(\bf \left. \begin{align} & \begin{matrix} \bf 17 \\ \bf 15 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\,\bf 2 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{5}{3} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \)
Viết: \(\bf 17 : 5 = 3\) (dư \(\bf 2\))
\(\left. \begin{align} & \begin{matrix} 19 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{3}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 29 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{6}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 19 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{4}{{}} \\ \end{matrix} \)
c) \(\left. \begin{align} & \begin{matrix} 20 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{3}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 28 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{4}{{}} \\ \end{matrix} \)
\(\left. \begin{align} & \begin{matrix} 46 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{5}{{}} \\ \end{matrix} \) \(\left. \begin{align} & \begin{matrix} 42 \end{matrix} \\ & \, \\ \end{align} \right|\begin{matrix} \dfrac{6}{{}} \\ \end{matrix} \)
Hướng dẫn :
Sử dụng các bảng chia đã học.
a)
\( \left. \begin{align} & \begin{matrix}20 \\ 20 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\, 0 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{5}{4} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(20 : 5 = 4\)
\( \left. \begin{align} & \begin{matrix}15 \\ 15 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\, 0 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{3}{5} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(15 : 3 = 5\)
\( \left. \begin{align} & \begin{matrix}24 \\ 24 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\, 0 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{4}{6} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(24 : 4 = 6\)
b)
\( \left. \begin{align} & \begin{matrix}19 \\ 18 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\, 1 \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{3}{6} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(19 : 3 = 6\) (dư \(1\))
\( \left. \begin{align} & \begin{matrix}29 \\ 24 \\ \end{matrix} \\ & \overline{\begin{align} &\,\, 5\,\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{6}{4} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(29 : 6 = 4\) (dư \(5\))
\( \left. \begin{align} & \begin{matrix}19 \\ 16 \\ \end{matrix} \\ & \overline{\begin{align} &\,\, 3\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{4}{4} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \(19 : 4 = 4\) (dư \(3\))
c)
\( \left. \begin{align} & \begin{matrix}20 \\ 18 \\ \end{matrix} \\ & \overline{\begin{align} &\,\, 2\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{3}{6} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \( \left. \begin{align} & \begin{matrix}28 \\ 28 \\ \end{matrix} \\ & \overline{\begin{align} &\,\,\, 0\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{4}{7} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \)
\( \left. \begin{align} & \begin{matrix}46 \\ 45 \\ \end{matrix} \\ & \overline{\begin{align} &\,\, \,1\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{5}{9} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \) \( \left. \begin{align} & \begin{matrix}42 \\ 42 \\ \end{matrix} \\ & \overline{\begin{align} &\,\, \, 0\, \\ \end{align}} \\ \end{align} \right|\begin{matrix} \dfrac{6}{7} \\ \begin{matrix} \end{matrix} {} \\ \end{matrix} \)