\[Страница\ 76.\]
\[\boxed{\mathbf{80.}}\]
\[6 \cdot 5 + 4 = 30 + 4 = 34\]
\[7 \cdot 8 - 6 = 56 - 6 = 50\]
\[28\ :7 \cdot 9 = 4 \cdot 9 = 36\]
\[64\ :8 + 7 = 8 + 7 = 15\]
\[\boxed{\mathbf{81.}}\]
\[Множитель\] | \[5\] | \[7\] | \[9\] | \[9\] | \[7\] | \[6\] | \[7\] |
---|---|---|---|---|---|---|---|
\[Множитель\] | \[8\] | \[9\] | \[4\] | \[8\] | \[8\] | \[9\] | \[7\] |
\[Произведение\] | \[40\] | \[63\] | \[36\] | \[72\] | \[56\] | \[54\] | \[49\] |
\[\boxed{\mathbf{82.}}\]
\[1)\ 7 - 7 = 0\]
\[2)\ 7 \cdot 0 = 0\]
\[\boxed{\mathbf{83.}}\]
\[Первый\ способ.\]
\[(68 - 20) - 25 = 48 - 25 =\]
\[= 23\ (рисунка) - осталось\ \]
\[сделать.\]
\[Второй\ способ.\]
\[(68 - 25) - 20 = 43 - 20 =\]
\[= 23\ (рисунка) - осталось\ \]
\[сделать.\]
\[Ответ:23\ рисунка.\]