Multiply by Multiples of 10, 100, 1,000
Round to estimate products
Arrays
Partial Products
Area Model
100
8×5=
80×5=
800×5=
8,000×5=
40
400
4,000
40,000
100
Estimate the product. Round the first factor to the nearest ten, and then multiply.
67 × 6
420
100
90
100
left
100
100
10
=110
200
7×8=
7×80=
7×800=
7×8,000=
56
560
5,600
56,000
200
Estimate the product. Round the first factor to the nearest ten, and then multiply.
72 × 8
560
200
3 x 347
=
1,041
200
28
40
800
= 868
200
3,200
240
32
=3,472
300
Ms. Murphy is setting up for the art show. She set up 3 boards for each of the 10 types of artwork. Then, she hung 6 projects on each of the boards. How many art projects are in the art show altogether?
180 Art Projects
300
Estimate the product. Round the first factor to the nearest hundred, and then multiply.
338 × 7
2,100
300
57
300
8,000
1,200
240
4
= 9,444
300
10,440
400
Mrs. Wallingford sells trading cards in boxes of 30. If she sells 5 boxes, how many trading cards did Mrs. Wallingford sell?
150 trading cards
400
Estimate the product. Round the second factor to the nearest hundred, and then multiply.
3 × 521
1,500
400
72
400
6
420
5,400
24,000
=29,826
400
A doctor's office ordered 8 shipments of bandages. There were 661 bandages in each shipment. How many bandages in total did the doctor's office order?
bandages
5,288
500
Jessica is training for a multi-sport race. She plans to do the same workout for 30 days. Today was the very first day, and she ran 3 miles and biked 6 miles. How many miles will Jessica have completed after all 30 days?
270 Miles
500
Estimate the product. Round the second factor to the nearest thousand, and then multiply.
7 × 6,773
49,000
500
136
500
36,552
500
A soup company ordered 4 shipments of carrots. There were 5,583 carrots in each shipment. How many carrots did the company order in all?
carrots
22,332