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Теория: 07 Вычитание трехзначных чисел

Задание

Найдите разность: 

\(\displaystyle -\)\(\displaystyle 3\)\(\displaystyle 4\)\(\displaystyle 2\)
\(\displaystyle 1\)\(\displaystyle 3\)\(\displaystyle 1\)
 

 

Решение

1. Из единиц числа \(\displaystyle 34\underline{2} \) (это цифра \(\displaystyle 2 \)) вычитаем единицы числа \(\displaystyle 13\underline{1}\) (это цифра \(\displaystyle 1\)):

\(\displaystyle 2-1=1.\)

\(\displaystyle -\)\(\displaystyle 3\)\(\displaystyle 4\)\(\displaystyle \color{red}{2}\)
\(\displaystyle 1\)\(\displaystyle 3\)\(\displaystyle \color{red}{1}\)
 \(\displaystyle ?\)\(\displaystyle ?\)\(\displaystyle \color{red}{\bf1}\)

 

2. Вычитаем из десятков числа \(\displaystyle 3\underline{4}2\) (это цифра \(\displaystyle 4\)) десятки числа \(\displaystyle 1\underline{3}1\) (это цифра \(\displaystyle 3\)):

\(\displaystyle 4-3=1.\)

\(\displaystyle -\)\(\displaystyle 3\)\(\displaystyle \color{red}{4}\)\(\displaystyle 2\)
\(\displaystyle 1\)\(\displaystyle \color{red}{3}\)\(\displaystyle 1\)
 \(\displaystyle ?\)\(\displaystyle \color{red}{\bf1}\)\(\displaystyle 1\)

 

3. Вычитаем из сотен числа \(\displaystyle \underline{3}42 \) (это цифра \(\displaystyle 3\)) сотни числа \(\displaystyle \underline{1}31\) (это цифра \(\displaystyle 1\)):

\(\displaystyle 3-1=2.\)

\(\displaystyle -\)\(\displaystyle \color{red}{3}\)\(\displaystyle 4\)\(\displaystyle 2\)
\(\displaystyle \color{red}{1}\)\(\displaystyle 3\)\(\displaystyle 1\)
 \(\displaystyle \color{red}{\bf2}\)\(\displaystyle 1\)\(\displaystyle 1\)


Ответ: \(\displaystyle 211.\)