题目：完成下列口算练习

1. 3 × 4 = _______ 5 × 7 = _______ 2 × 8 = _______

2. 9 × 1 = _______ 4 × 6 = _______ 7 × 5 = _______

3. 6 × 2 = _______ 8 × 3 = _______ 5 × 4 = _______

4. 10 - 7 = _______ 12 - 9 = _______ 15 - 8 = _______

5. 20 + 5 = _______ 18 + 7 = _______ 23 + 9 = _______

6. 50 - 20 = _______ 40 - 10 = _______ 30 - 8 = _______

7. 7 × 7 = _______ 9 × 9 = _______ 6 × 6 = _______

8. 8 × 8 = _______ 10 × 10 = _______ 5 × 5 = _______

9. 14 - 7 = _______ 21 - 9 = _______ 16 - 8 = _______

10. 23 + ( ) = 30 ( ) + 17 = 25 ( ) + ( ) = ( )

1. 12；35；16

2. 9；24；35

3. 12；24；20

4. 3；3；7

5. 25；25；32

6. 30；30；22

7. 49；81；36

8. 64；100；25

9. 7；12；8

10. ( )填法不唯一，如：6、8、8、16