Задание
Найти сумму:
| \(\displaystyle +\) | \(\displaystyle 1\) | \(\displaystyle 1\) | \(\displaystyle 2\) |
| \(\displaystyle 1\) | \(\displaystyle 3\) | \(\displaystyle 9\) | |
Решение
1. Сначала сложим единицы: \(\displaystyle 2+9=11.\)
Пишем \(\displaystyle 1\) (единицы числа \(\displaystyle 1\underline{1},\)) а \(\displaystyle 1\) (десятки числа \(\displaystyle \underline{1}1 \)) переходит на сложение следующих разрядов.
| 1 | |||
| \(\displaystyle +\) | \(\displaystyle 1\) | \(\displaystyle 1\) | \(\displaystyle \color{red}{2}\) |
| \(\displaystyle 1\) | \(\displaystyle 3\) | \(\displaystyle \color{red}{9}\) | |
| \(\displaystyle ?\) | \(\displaystyle ?\) | \(\displaystyle \color{red}{\bf1}\) |
2. Складываем десятки \(\displaystyle 1+3\) и добавляем \(\displaystyle 1,\) перешедшую с прошлого действия, то есть \(\displaystyle 1+3+1=5.\)
| +1 | |||
| \(\displaystyle +\) | \(\displaystyle 1\) | \(\displaystyle \color{red}{1}\) | \(\displaystyle 2\) |
| \(\displaystyle 1\) | \(\displaystyle \color{red}{3}\) | \(\displaystyle 9\) | |
| \(\displaystyle ?\) | \(\displaystyle \color{red}{\bf5}\) | \(\displaystyle 1\) |
3. Складываем сотни: \(\displaystyle 1+1=2.\)
| \(\displaystyle +\) | \(\displaystyle \color{red}{1}\) | \(\displaystyle 1\) | \(\displaystyle 2\) |
| \(\displaystyle \color{red}{1}\) | \(\displaystyle 3\) | \(\displaystyle 9\) | |
| \(\displaystyle \color{red}{\bf2}\) | \(\displaystyle 5\) | \(\displaystyle 1\) |
Ответ: \(\displaystyle 251.\)