Question

[Buddy]

a) Tính nhẩm: 

b) Đặt tính rồi tính:

c) Tính:   

42 + 18 – 10                                              60 – 13 + 23

Answer 1

[Hà Quang Minh]

a) 8 + 4 = 12               15 – 6 = 9                9 + 2 = 11                 6 + 8 = 14

   4 + 8 = 12                15 – 9 = 6               11 – 9 = 2                  14 – 8 = 6

b)

\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{48}\\{27}\end{array}}\\\hline{\,\,\,75}\end{array}\)                             \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{25}\\{75}\end{array}}\\\hline{\,100}\end{array}\)                                \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{80}\\{\,\,7}\end{array}}\\\hline{\,\,\,73}\end{array}\)                          \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{100}\\{\,\,\,\,\,8}\end{array}}\\\hline{\,\,\,\,\,\,92}\end{array}\)

\(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{82}\\{55}\end{array}}\\\hline{\,\,\,27}\end{array}\)                             \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{50}\\{39}\end{array}}\\\hline{\,\,\,11}\end{array}\)                                \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{91}\\{\,\,9}\end{array}}\\\hline{100}\end{array}\)                          \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{100}\\{\,\,28}\end{array}}\\\hline{\,\,\,\,\,72}\end{array}\)

c) 42 + 18 – 10 = 60 – 10 = 50

   60 – 13 + 23 = 47 + 23 = 70