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Теория: Умножение двузначных чисел

Задание

Перемножить числа:

  \(\displaystyle \times\)\(\displaystyle 7\)\(\displaystyle 2\)
 \(\displaystyle 3\)\(\displaystyle 6\)
\(\displaystyle +\) 
 
 

 

Решение

1. Умножаем единицы числа \(\displaystyle 3\underline{6} \) (это цифра \(\displaystyle 6\)) на число \(\displaystyle 72{\small : }\)

 

\(\displaystyle 6\cdot 72=432{\small . }\)

 

  \(\displaystyle \times\)\(\displaystyle \bf 7\)\(\displaystyle \bf 2\)
 \(\displaystyle 3\)\(\displaystyle \bf 6\)
\(\displaystyle +\) \(\displaystyle \bf 4\)\(\displaystyle \bf 3\)\(\displaystyle \bf 2\)
\(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle ?\) 
 \(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle ?\)

 

2. Умножаем десятки числа \(\displaystyle \underline{3}6\) (это цифра \(\displaystyle 3\)) на число \(\displaystyle 72{\small : }\)

 

\(\displaystyle 3\cdot 72=216{\small . }\)

 

  \(\displaystyle \times\)\(\displaystyle \bf 7\)\(\displaystyle \bf 2\)
 \(\displaystyle \bf 3\)\(\displaystyle 6\)
\(\displaystyle +\) \(\displaystyle 4\)\(\displaystyle 3\)\(\displaystyle 2\)
\(\displaystyle \bf 2\)\(\displaystyle \bf 1\)\(\displaystyle \bf 6\) 
 \(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle ?\)

 

3. Складываем числа:

\(\displaystyle +\) \(\displaystyle 4\)\(\displaystyle 3\)\(\displaystyle 2\)
\(\displaystyle 2\)\(\displaystyle 1\)\(\displaystyle 6\)  
 \(\displaystyle 2\)\(\displaystyle 5\)\(\displaystyle 9\)\(\displaystyle 2\)

 

В итоге мы получаем:

  \(\displaystyle \times\)\(\displaystyle 7\)\(\displaystyle 2\)
 \(\displaystyle 3\)\(\displaystyle 6\)
\(\displaystyle +\) \(\displaystyle 4\)\(\displaystyle 3\)\(\displaystyle 2\)
\(\displaystyle 2\)\(\displaystyle 1\)\(\displaystyle 6\) 
 \(\displaystyle 2\)\(\displaystyle 5\)\(\displaystyle 9\)\(\displaystyle 2\)

Ответ: \(\displaystyle 2592{\small . }\)