Решебник по математике 4 класс Кремнева рабочая тетрадь Часть 1, 2 Часть 2 | Страница 24

\[\boxed{\mathbf{Стр.\ 24.\ }еуроки - ответы\ на\ пятёрку}\]

\[\boxed{\mathbf{1.}}\]

\[1)\ 72\ дм^{2} = 7200\ см^{2}\]

\[300\ мм^{2} = 3\ см^{2}\]

\[2\ м^{2} = 20\ 000\ см^{2}\]

\[20\ дм^{2} = 2000\ см^{2}\]

\[4000\ мм^{2} = 40\ см^{2}\]

\[2)\ 410\ м^{2} = 41\ 000\ дм^{2}\]

\[80\ 000\ мм^{2} = 8\ дм^{2}\]

\[87\ м^{2} = 8700\ дм^{2}\]

\[9400\ см^{2} = 94\ дм^{2}\]

\[100\ 000\ мм^{2} = 10\ дм^{2}\]

\[\boxed{\mathbf{2.}}\]

\[3 \cdot 80 = 240 + 500 = 740\]

\[4 \cdot 80 = 320 + 500 = 820\]

\[5 \cdot 80 = 400 + 500 = 900\]

\[6 \cdot 80 = 480 - 199 = 281\]

\[7 \cdot 80 = 560 - 199 = 361\]

\[\boxed{\mathbf{3.}}\]

\[370\ :18 = 20\ (ост.\ 10)\]

\[3229\ :40 = 80\ (ост.\ 29)\]

\[910\ :45 = 20\ (ост.\ 10)\]

\[900\ :7 = 128\ (ост.\ 4)\]

\[390\ :40 = 9\ (ост.\ 30)\]

\[500\ :80 = 6\ (ост.\ 20)\]

\[360\ :50 = 7\ (ост.\ 10)\]

\[760\ :80 = 9\ (ост.\ 40)\]

\[1250\ :60 = 20\ (ост.\ 50)\]

\[\boxed{\mathbf{4.}}\]

\[400 \cdot 80 = 32\ 000 \cdot 20 =\]

\[= 640\ 000\ :8000 = 80 \cdot 50 =\]

\[= 4000\ :1000 =\]

\[= 4 \cdot 90 = 360\ :60 = 6 \cdot 30 =\]

\[= 180\ :90 = 2.\]