\[\boxed{Стр.\ \mathbf{103}\text{.\ \ }\mathbf{ОК\ ГДЗ\ - \ домашка\ на\ 5}}\]
\[Свойства\ сложения\]
\[\boxed{\mathbf{3}.}\]
\[От\ перемены\ мест\ слагаемых\ \]
\[сумма\ не\ меняется\ \]
\[(переместительный\ \]
\[закон\ сложения):\]
\[8 + 76 = 76 + 8.\]
\[Два\ соседних\ слагаемых\ можно\ \]
\[заменить\ суммой\ \]
\[(сочетательный\ закон\ \]
\[сложения):\]
\[(18 + 17) + 3 = 18 + (17 + 3).\]
\[\boxed{\mathbf{4}.}\]
\[1)\ 27 + 36 + 4 + 13 =\]
\[= (27 + 13) + (36 + 4) =\]
\[= 40 + 40 = 80\]
\[45 + 8 + 5 + 12 =\]
\[= (45 + 5) + (8 + 12) =\]
\[= 50 + 20 = 70\]
\[= 10 + 10 + 10 + 10 + 5 = 45.\]
\[Таблица\ сложения\]
\[\boxed{\mathbf{5}.}\]
\[11 = 5 + 6\]
\[11 = 9 + 2\]
\[11 = 4 + 7\]
\[11 = 8 + 3\]
\[12 = 6 + 6\]
\[12 = 9 + 3\]
\[12 = 7 + 5\]
\[12 = 4 + 8\]
\[13 = 7 + 6\]
\[13 = 4 + 9\]
\[13 = 5 + 8\]
\[14 = 5 + 9\]
\[14 = 8 + 6\]
\[14 = 7 + 7\]
\[15 = 8 + 7\]
\[15 = 6 + 9\]
\[16 = 7 + 9\]
\[16 = 8 + 8\]
\[17 = 8 + 9\]
\[18 = 9 + 9\]
\[\boxed{\mathbf{6}.}\]
\[1)\ 5 + 6 = 11\]
\[7 + 8 = 15\]
\[6 + 6 = 12\]
\[8 + 5 = 13\]
\[9 + 2 = 11\]
\[4 + 8 = 12\]
\[5 + 9 = 14\]
\[2)\ 16 - 8 = 8\]
\[14 - 5 = 9\]
\[12 - 7 = 5\]
\[11 - 6 = 5\]
\[12 - 3 = 9\]
\[13 - 9 = 4\]
\[14 - 7 = 7\]
\[3)\ 7 + 5 = 12\]
\[9 + 4 = 13\]
\[8 + 8 = 16\]
\[7 + 6 = 13\]
\[8 + 3 = 11\]
\[4 + 7 = 11\]
\[7 + 9 = 16\]
\[4)\ 11 - 4 = 7\]
\[12 - 6 = 6\]
\[13 - 4 = 9\]
\[14 - 8 = 6\]
\[15 - 7 = 8\]
\[18 - 9 = 9\]
\[12 - 8 = 4\]
\[\boxed{\mathbf{Задание\ на\ полях}.\ Продолжи\ ряд}\]
\[31 - 2\]
\[30 - 3\]
\[29 - 4\]
\[28 - 5\]
\[27 - 6\]
\[26 - 7\]
\[25 - 8\]