Multiply by Multiples 10, 100 & 1,000
Mental Math: Round to Estimate Products
The Distributive Property
We say "Partial Products"
We think "Place Value"
Possible Test Questions
100

3 x 70= 

210

100

6 x 112=

 About 600

100

Use Distributive to solve (box method)

5 x 921=

(5 x900) + (5x20) + (5x1) =

4,500 + 100 + 5 = 4,601

100
Solve using Partial Products


227 x 3 =

(rewrite it) 

681

100

solve using the standard algorithm 

5,276 x 4= 

21,104

200

6 x 400=

2,400

200

4 x 2,610=

About 12,000

200

Use Distributive to solve (box method)

4 x 352=

(4 x 300) + (4 x 50) + (4 x 2) =

1,200 + 200 + 8 = 1,408

200

solve using partial products

1,165 x 7 =

(rewrite it)

8,155

200

In each of 3 games last month, Julia's bowling score was 195. Use compensation to find the total score for Julia's 3 games.

 **hint: 195 is close to 200


195 is close to 200 so 

200 x 3 = 600

600- 15= 585

300

8 x 6,000= 

48,000


300

3 x 287=

Round 287 to ____

3 x ______= ______

3 x 300= 900

300

Use Distributive Property to solve

6 x 310= 6 (300 x ____)

           = (6 x ____) + (____ x 10)

           = _______ + _______

           = ___________

1,860

300

Solve using partial products

4,826 x 6 =

28,956

300

Mrs. Wallford is selling boxes of cards in boxes of 30 and boxes of 60. If she sells 5 boxes of 60, how many trading cards did Mrs. Wallford sell?


300 trading cards

400

7,000 x 4=

28,000

400

5 x 1,240 = 9,200

Is this reasonable?

Round 1,240 to ______.

5 x _____= _______.

5 x 1,000= 5,000

9,200 is not reasonable.

400
Use Distributive Property to solve


4 x 1,554 = _________

6,216

400
use partial products to solve 


2,459 x 7 = 

17,213

400

Select all the partial products for  7 x 532.

a. 14 

b. 35

c. 210

d. 3,500

e. 4,000

a. 14

b. 210

c. 3,500

500

The Mississippi River is about 8 times the length of the Hudson River. If the Hudson River is about 300 miles long, about how many miles is the Missippi River?

8 x 300= m

m= 2,400

About 2,400 miles

500

Elle estimates the product of 211 and 6 is 1,800. Is this estimate reasonable? Explain.

No.

211 should be rounded to 200 and then multiplied by 6 to get 1,200. 

200 x 6= 1,200

500

A lodge at a state park has 49 rooms. Up to 5 people can stay in each room. What is the maximum number of people who can at stay the lodge at one time?

 ______ toes?

245 people 

500

Tommy spent $259 on 4 computers each. Use partial products to find out how much money Tommy spent in total. 

$1,036

500

a carpenter bought 3 boxes of nails. Each box is 218 nails. Which is the best estimate for the total number of nails purchased?

200

400

500

600

600

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