Product Patterns
3 x 4
3 x 40
3 x 400
3 x 4000
12, 120, 1,200, 1,2000
Ifenna says the product of 5 x 67 is about 350. Is he correct?
Yes, 67 rounds to 70. 70 X 5 is 350, so his answer is reasonable.
Use Partial Products to solve the following problem:
627 x 6
3,762
Use the area model to solve the following problem:
7,653 x 7
53,571
5 x 5
5 x 50
5 x 500
5 x 5,000
25, 250, 2,500, 25,000
Tommy says 49 x 4 is about 500. Is his answer reasonable? Why or why not?
No, his answer is not reasonable because 49 rounds to 50, and 50 x 4 is 200. So no, his answer is not reasonable because 200 is not close to 500.
Use Partial Products to solve the following problem:
8521 x 7
59,647
What are the partial products you would add to solve:
3,782 x 3
9,000+2,100+240+6
9 x 9
9 x 90
9 x 900
9 x 9000
81, 810, 8,100, 81,000
True or false: 32x3 is about 90.
Use Partial Products to solve the following problem:
7336 x 3
22,008
What are the partial products for:
8345 x 3
24,000+900+120+15
6 x 7
6 x 70
6 x 700
6 x 7000
42, 420, 4,200, 42,000
What is the estimated product of 89 x 2?
90 x 2=180
Use Partial Products to solve the following problem:
5758 x 9
51,822
What are the partial products for:
5634 x 7
35,000+4,200+210+28
7 x 4
7 x 40
7 x 400
7 x 4000
28, 280, 2,800, 28,000
What is the estimated product of 18 x 6?
20 x 6= 120.
Use the area model to solve the following problem:
3,345 x 5
16,725
Solve for:
5837 x 7
40,859