实践应用第1题答案
38 - (8 + 30)
= 38 - 38
= 0
5×(18 - 12)
= 5 × 6
= 30
(45 - 10) ÷ 5
= 35 ÷ 5
= 7
实践应用第2题答案
16 + 24 ÷ 8
= 16 + 3
= 19
(16 + 24) ÷ 8
= 40 ÷ 8
= 5
18 - 9 × 2
= 18 - 18
= 0
(18 - 9) × 2
= 9 × 2
= 18
实践应用第3题答案
34 + 8 × 2
= 34 + 16
= 50(人)
达标检测第1题答案
前两道题不对。
12 + 12 ÷ 6
= 12 + 2
= 14
42 - (22 - 9)
= 42 - 13
= 29
达标检测第2题答案
63 ÷ (36 - 29)
= 63 ÷ 7
= 9
99 - (46 + 34)
= 99 - 80
= 19
(110 - 80) ÷ 5
= 30 ÷ 5
= 6
达标检测第3题答案
100 - 9 × 5
= 100 - 45
= 55(只)