实践应用第1题答案
4 + 4 + 4 = 12
3 × 4 = 12
4 × 3 = 12
实践应用第2题答案
3 + 3 = 6
2 × 3 = 6
3 × 2 = 6
实践应用第3题答案
(1)4 + 4 = 8 4 × 2 = 8 2 × 4 = 8
(2)2 + 2 + 2 + 2 + 2 = 10
2 × 5 = 10 5 × 2 = 10
实践应用第4题答案
1 + 1 + 2 = 4(个) 4 × 3 = 12(个)
达标检测第1题答案
略
达标检测第2题答案
(1)4 × 3
(2)2 + 2 + 2
(3)5 × 3
达标检测第3题答案
4 + 4 + 4 + 4 + 4 = 20 4 × 5 = 20 5 × 4 = 20