Страница 30, ГДЗ по математике за 3 класс к тренажёру Погореловой
Внетабличное умножение и деление с круглыми числами
\[\begin{aligned} 3 \cdot 20 &= \textcolor{#e03131}{\mathbf{60}} & \qquad 2 \cdot 2 \cdot 10 &= \textcolor{#e03131}{\mathbf{40}} \\ 4 \cdot 10 &= \textcolor{#e03131}{\mathbf{40}} & \qquad 3 \cdot 2 \cdot 10 &= \textcolor{#e03131}{\mathbf{60}} \\ 2 \cdot 40 &= \textcolor{#e03131}{\mathbf{80}} & \qquad 2 \cdot 4 \cdot 10 &= \textcolor{#e03131}{\mathbf{80}} \\ 3 \cdot 30 &= \textcolor{#e03131}{\mathbf{90}} & \qquad 3 \cdot 3 \cdot 10 &= \textcolor{#e03131}{\mathbf{90}} \\ 2 \cdot 20 &= \textcolor{#e03131}{\mathbf{40}} & \qquad 2 \cdot 3 \cdot 10 &= \textcolor{#e03131}{\mathbf{60}} \end{aligned}\]
\[\begin{aligned} 40 : 2 &= \textcolor{#e03131}{\mathbf{20}} & \qquad 90 : 3 &= \textcolor{#e03131}{\mathbf{30}} & \qquad 100 : 10 &= \textcolor{#e03131}{\mathbf{10}} \\ 7 \cdot 10 &= \textcolor{#e03131}{\mathbf{70}} & \qquad 2 \cdot 20 &= \textcolor{#e03131}{\mathbf{40}} & \qquad 5 \cdot 20 &= \textcolor{#e03131}{\mathbf{100}} \\ 60 : 3 &= \textcolor{#e03131}{\mathbf{20}} & \qquad 80 : 2 &= \textcolor{#e03131}{\mathbf{40}} & \qquad 100 : 50 &= \textcolor{#e03131}{\mathbf{2}} \\ 3 \cdot 30 &= \textcolor{#e03131}{\mathbf{90}} & \qquad 3 \cdot 20 &= \textcolor{#e03131}{\mathbf{60}} & \qquad 20 \cdot 5 &= \textcolor{#e03131}{\mathbf{100}} \\ 80 : 4 &= \textcolor{#e03131}{\mathbf{20}} & \qquad 60 : 2 &= \textcolor{#e03131}{\mathbf{30}} & \qquad 100 : 20 &= \textcolor{#e03131}{\mathbf{5}} \end{aligned}\]
\[\begin{aligned} 4 \cdot \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{2}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} &= 80 & \qquad 3 \cdot \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{2}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} &= 60 \\ \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{1}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} \cdot 5 &= 50 & \qquad \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{4}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} : 2 &= 20 \\ \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{4}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} : 4 &= 10 & \qquad 2 \cdot \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{4}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} &= 80 \\ \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{9}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} : 3 &= 30 & \qquad \boxed{\kern0.035em\textcolor{#e03131}{\mathbf{6}}\kern0.035em}\hspace{-0.04em}\boxed{\kern0.035em\textcolor{#e03131}{\mathbf{0}}\kern0.035em} : 2 &= 30 \end{aligned}\]
