次の計算をしましょう。
問１
333 – 3 × ( 82 – 60 ÷ 4 ) – 15 × 4 =
- 答え
- 72
- 解き方
- 333 – 3 × ( 82 – 60 ÷ 4 ) – 15 × 4
= 333 – 3 × ( 82 – 15 ) – 60
= 333 – 3 × 67 – 60
= 333 – 201 – 60 = 72
問２
( 100 + 8 ) × 7 – ( 31 – 80 ÷ 5 ) × 17 ÷ 5 =
- 答え
- 705
- 解き方
- ( 100 + 8 ) × 7 – ( 31 – 80 ÷ 5 ) × 17 ÷ 5
= 108 × 7 – ( 31 – 16 ) × 17 ÷ 5
= 756 – \(\cancelto{3}{15}\) × 17 × \(\dfrac{1}{\cancel{5}}\)
= 756 – 51 = 705
問３
34 – { 850 – 1150 ÷ ( 60 – 2 × 7 ) } ÷ 25 =
- 答え
- 1
- 解き方
- 34 – { 850 – 1150 ÷ ( 60 – 2 × 7 ) } ÷ 25
= 34 – { 850 – 1150 ÷ ( 60 – 14 ) } ÷ 25
= 34 – { ( 850 – 1150 ÷ 46 ) × \(\dfrac{1}{25}\) }
= 34 – ( \(\cancelto{34}{850}\) × \(\dfrac{1}{\cancel{25}}\) – \(\cancelto{\cancel{46}}{1150}\) × \(\dfrac{1}{\cancel{46}}\) × \(\dfrac{1}{\cancel{25}}\) )
= 34 – ( 34 – 1 ) = 34 – 33 = 1
問４
{ ( 75 – 57 ) × 3 + 24 } ÷ 6 – 12 × 3 ÷ 6 =
- 答え
- 7
- 解き方
- { ( 75 – 57 ) × 3 + 24 } ÷ 6 – 12 × 3 ÷ 6
= ( 18 × 3 + 24 ) ÷ 6 – 6
= ( 54 + 24 ) ÷ 6 – 6
= ( 9 + 4 ) – 6 = 13 – 6 = 7
問５
21 – { 150 ÷ 25 + ( 113 – 99 ) × 3 ÷ 7 } =
- 答え
- 9
- 解き方
- 21 – { 150 ÷ 25 + ( 113 – 99 ) × 3 ÷ 7 }
= 21 – ( 6 + 14 × 3 ÷ 7 )
= 21 – ( 6 + 6 ) = 21 – 12 = 9
問６
396 ÷ ( 72 – 6 ) – 6 =
- 答え
- 0
- 解き方
- 396 ÷ ( 72 – 6 ) – 6
= 396 ÷ 66 – 6 = 6 – 6 = 0
問７
27 – { 154 – 7 × ( 7 – 5 ) } ÷ 7 =
- 答え
- 7
- 解き方
- 27 – { 154 – 7 × ( 7 – 5 ) } ÷ 7
= 27 – ( 154 – 7 × 2 ) ÷ 7
= 27 – ( 154 – 14 ) ÷ 7
= 27 – 140 ÷ 7 = 27 – 20 = 7
問８
( 17 × 9 + 18 ) ÷ 19 + 18 × 9 =
- 答え
- 171
- 解き方
- ( 17 × 9 + 18 ) ÷ 19 + 18 × 9
= ( 153 + 18 ) ÷ 19 + 18 × 9
= 171 ÷ 19 + 162
= 9 + 162 = 171
問９
2021 + { 59 – 2 × ( 121 – 92 ) } =
- 答え
- 2022
- 解き方
- 2021 + { 59 – 2 × ( 121 – 92 ) }
= 2021 + ( 59 – 2 × 29 )
= 2021 + ( 59 – 58 ) = 2021 + 1 = 2022
問１０
( 119 ÷ 17 – 51 ÷ 17 ) × { ( 119 – 51 ) ÷ 17 + 1 } =
- 答え
- 20
- 解き方
- ( 119 ÷ 17 – 51 ÷ 17 ) × { ( 119 – 51 ) ÷ 17 + 1 }
= ( 7 – 3 ) × ( 7 – 3 + 1 )
= 4 × 5 = 20