Ответы к учебнику по математике за 2 класс 1 часть Рудницкая. Умножение числа 2. Умножение и деление на 2. Половина числа. Номер №31

Выполни действия.
57 + 20
67 − 9
35 + 27
83 − 40
60 + 30
27 + 17
72 − 7
83 − 21
38 − 22
100 − 23
46 + 48
54 + 39

Ответ

57 + 20 = 77
67 − 9 = 58
35 + 27 = 62
83 − 40 = 43
60 + 30 = 90
27 + 17 = 44
72 − 7 = 65
83 − 21 = 62
38 − 22 = 16
100 − 23 = 77
46 + 48 = 94
54 + 39 = 93
Вычисления:

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}57\\ 20\end{array}}\\ \begin{array}{r}77\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}67\\ 9\end{array}}\\ \begin{array}{r}58\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}35\\ 27\end{array}}\\ \begin{array}{r}62\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}83\\ 40\end{array}}\\ \begin{array}{r}43\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}60\\ 30\end{array}}\\ \begin{array}{r}90\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}27\\ 17\end{array}}\\ \begin{array}{r}44\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}72\\ 7\end{array}}\\ \begin{array}{r}65\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}83\\ 21\end{array}}\\ \begin{array}{r}62\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}38\\ 22\end{array}}\\ \begin{array}{r}16\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}—\end{array}\underline{\begin{array}{r}100\\ 23\end{array}}\\ \begin{array}{r}77\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}48\\ 48\end{array}}\\ \begin{array}{r}94\end{array}\end{array}$

$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}54\\ 39\end{array}}\\ \begin{array}{r}93\end{array}\end{array}$