Name _________________________________________________
4 as a Factor: Doubling
Find each product.
1.
4
3 6
2.
5
3 4
3.
8
3 4
4.
4
3 7
5.
1
3 4
6.
7
34
7.
4
3 9
8.
4
3 2
9.
4
3 4
10.
4
3 3
11. 4 3 4
12. 4 3 7
13. 4 3 1
14. 5 3 4
15. 2 3 4
16. 3 3 4
17. 2 3 4
18. 9 3 4
19. Multiply 7 by 4.
20. Multiply 4 by 8.
21. What is the product of
22. What is the product of
4 and 5?
23. Draw arrays to show that
4 3 6 is the same as 6 3 4.
© 2000 – 2007 Pearson Education, Inc. All Rights Reserved.
4 and 9?
24. Could you use doubling to
multiply 9 3 3? Explain.
Answer Key
4 as a Factor: Doubling
Find each product.
1.
2.
4
3 6
24
6.
3.
5
3 4
7.
4
3 9
8.
36
28
4
3 2
12. 4 3 7
16
28
15. 2 3 4
16. 3 3 4
8
12
19. Multiply 7 by 4.
28
5.
4
3 7
1
3 4
28
9.
4
4
3 4
10.
16
8
11. 4 3 4
4
3 3
12
13. 4 3 1
14. 5 3 4
4
20
17. 2 3 4
18. 9 3 4
36
8
20. Multiply 4 by 8.
32
21. What is the product of
4 and 5?
4.
32
20
7
3 4
8
3 4
20
23. Draw arrays to show that
4 3 6 is the same as 6 3 4.
Arrays should show 4 groups
of 6 and 6 groups of 4.
© 2000 – 2007 Pearson Education, Inc. All Rights Reserved.
22. What is the product of
4 and 9?
36
24. Could you use doubling to
multiply 9 3 3? Explain.
No; neither 9 nor 3 is a
multiple of 2.