Часть 2 страница 20, ГДЗ по математике за 4 класс к рабочей тетради Дорофеева
Умножение на 10, 100, 1 000, 10 000 и 100 000. Деление числа, которое оканчивается нулями, на 10, 100, 1 000, 10 000 и 100 000
\[\begin{aligned} 38 \cdot 10\,000 &= \underline{\kern0.4em\textcolor{#e03131}{\mathbf{380\,000}}\kern0.4em} & \qquad 205\,000 : 100 &= \underline{\kern0.4em\textcolor{#e03131}{\mathbf{2\,050}}\kern0.4em} \\ 147 \cdot 100 &= \underline{\kern0.4em\textcolor{#e03131}{\mathbf{14\,700}}\kern0.4em} & \qquad 60\,000 : 1\,000 &= \underline{\kern0.4em\textcolor{#e03131}{\mathbf{60}}\kern0.4em} \end{aligned}\]
\[{\def\arraystretch{1.6}\begin{array}{l} \mathrlap{\vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}}\hspace{0.39em}\mathclap{\vcenter{\rule[-0.144em]{0pt}{0.144em}\textcolor{#e03131}{\footnotesize\pmb{\boldsymbol{?}}}}}\hspace{0.39em}\enspace \overset{\textcolor{#808080}{\scriptstyle 110\,000\text{ мм}}}{110\text{ м},}\enspace \overset{\textcolor{#808080}{\scriptstyle 110\,000\text{ мм}}}{1\,100\text{ дм},}\ 110\,000\text{ мм} \\ \mathrlap{\vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}}\hspace{0.39em}\mathclap{\vcenter{\rule[-0.28em]{0pt}{0.28em}\textcolor{#e03131}{\scriptsize\pmb{\boldsymbol{\downarrow}}}}}\hspace{0.39em}\enspace \overset{\textcolor{#808080}{\scriptstyle 110\,000\text{ дм}}}{11\text{ км},}\ 11\,000\text{ дм},\ \overset{\textcolor{#808080}{\scriptstyle 10\,100\text{ дм}}}{101\,000\text{ см}} \\ \mathrlap{\vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}}\hspace{0.39em}\mathclap{\vcenter{\rule[-0.144em]{0pt}{0.144em}\textcolor{#e03131}{\footnotesize\pmb{\boldsymbol{?}}}}}\hspace{0.39em}\enspace \overset{\textcolor{#808080}{\scriptstyle 110\,000\text{ см}^2}}{11\text{ м}^2,}\enspace \overset{\textcolor{#808080}{\scriptstyle 110\,000\text{ см}^2}}{1\,100\text{ дм}^2,}\ 101\,000\text{ см}^2 \\ \mathrlap{\vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}}\hspace{0.39em}\mathclap{\vcenter{\rule[-0.28em]{0pt}{0.28em}\textcolor{#e03131}{\scriptsize\pmb{\boldsymbol{\downarrow}}}}}\hspace{0.39em}\enspace \overset{\textcolor{#808080}{\scriptstyle 10\,100\text{ см}^2}}{101\text{ дм}^2,}\ 1\,010\text{ см}^2,\ \overset{\textcolor{#808080}{\scriptstyle 1\,000\text{ см}^2\text{ }1\text{ мм}^2}}{100\,001\text{ мм}^2} \end{array}}\] \(\textcolor{#808080}{\text{Величины 110 м, 1\,100 дм}}\) \(\textcolor{#808080}{\text{и 110\,000 мм равны,}}\) \(\textcolor{#808080}{{11\text{ м}^2 = 1\,100\text{ дм}^2}\text{.}}\) \(\textcolor{#808080}{\text{Если равенство не нарушает}}\) \(\textcolor{#808080}{\text{порядка, ряд }{11\text{ м}^2}\text{,}}\) \(\textcolor{#808080}{{1\,100\text{ дм}^2}\text{, }{101\,000\text{ см}^2}\text{ —}}\) \(\textcolor{#808080}{\text{убывающий.}}\)
\(250 \cdot 10 = \textcolor{#e03131}{\mathbf{2\,500}}\text{ (д.)}\)
Ответ: \(\textcolor{#e03131}{\mathbf{2\,500}}\) деталей.
\(1\text{ мин }30\text{ с} = \textcolor{#e03131}{\mathbf{90}}\text{ с}\)
\(1)\ 1\,500 : 100 = \textcolor{#e03131}{\mathbf{15}}\text{ (раз)}\)
\(2)\ 90 : 15 = \textcolor{#e03131}{\mathbf{6}}\text{ (с)}\)
Ответ: за \(\textcolor{#e03131}{\mathbf{6}}\) с.
\[{\def\arraystretch{1.3}\begin{array}{l} \vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}\enspace 50\,200 \mathbin{\overset{\text{\textcircled{1}}}{\vphantom{+}-}} (6\,100 \mathbin{\overset{\text{\textcircled{2}}}{+}} 1\,800 \mathrel{\overset{\text{\textcircled{3}}}{\vphantom{+}{:}}} 2) \mathbin{\overset{\text{\textcircled{4}}}{\vphantom{+}\cdot}} 7 = \underline{\kern0.4em\phantom{\textcolor{#e03131}{\boldsymbol{1\,200}}}\kern0.4em} \\ \vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}\enspace 50\,200 \mathbin{\overset{\text{\textcircled{3}}}{\vphantom{+}-}} (6\,100 \mathbin{\overset{\text{\textcircled{1}}}{+}} 1\,800 \mathrel{\overset{\text{\textcircled{2}}}{\vphantom{+}{:}}} 2) \mathbin{\overset{\text{\textcircled{4}}}{\vphantom{+}\cdot}} 7 = \underline{\kern0.4em\phantom{\textcolor{#e03131}{\boldsymbol{1\,200}}}\kern0.4em} \\ \vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}\enspace 50\,200 \mathbin{\overset{\text{\textcircled{3}}}{\vphantom{+}-}} (6\,100 \mathbin{\overset{\text{\textcircled{2}}}{+}} 1\,800 \mathrel{\overset{\text{\textcircled{1}}}{\vphantom{+}{:}}} 2) \mathbin{\overset{\text{\textcircled{4}}}{\vphantom{+}\cdot}} 7 = \underline{\kern0.4em\phantom{\textcolor{#e03131}{\boldsymbol{1\,200}}}\kern0.4em} \\ \mathrlap{\vcenter{\rule[-0.484em]{0pt}{0.484em}\boxed{\rule{0pt}{0.1em}\hspace{0.18em}}}}\hspace{0.39em}\mathclap{\vcenter{\rule[-0.224em]{0pt}{0.224em}\textcolor{#e03131}{\footnotesize\pmb{\mathrlap{\checkmark}\mathrlap{\kern0.04em\checkmark}\kern0.08em\checkmark}}}}\hspace{0.39em}\enspace \textcolor{#e03131}{\boldsymbol{50\,200 \mathbin{\overset{\textbf{\textcircled{4}}}{\vphantom{+}-}} (6\,100 \mathbin{\overset{\textbf{\textcircled{2}}}{+}} 1\,800 \mathrel{\overset{\textbf{\textcircled{1}}}{\vphantom{+}{:}}} 2) \mathbin{\overset{\textbf{\textcircled{3}}}{\vphantom{+}\cdot}} 7}} = \underline{\kern0.4em\textcolor{#e03131}{\boldsymbol{1\,200}}\kern0.4em} \end{array}}\] \(\textcolor{#808080}{{1\,800 : 2 = 900}\text{,}}\) \(\textcolor{#808080}{{6\,100 + 900 = 7\,000}\text{,}}\) \(\textcolor{#808080}{{7\,000 \cdot 7 = 49\,000}\text{,}}\) \(\textcolor{#808080}{{50\,200 - 49\,000 = 1\,200}}\)
