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

Type of Muffin     Number of Orders (boxes)

Blueberry                     53

Corn                            76

Coffee Crumb               30

Raspberry                    18

Calton Bakery sells a variety of muffins. There are 8 muffins in each box. How many blueberry muffins were ordered.

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

4,826 x 6 =

28,956

200

A parking garage has 8 levels.  


Each level has space for 78 cars. How many cars can park in the garage at one time?

300

8 x 6,000= 

48,000


300

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.

300

Use Distributive Property to solve


4 x 1,554 = _________

6,216

300

use partial products to solve 


2,459 x 7 = 

17,213

300

Mrs. Wallford is selling boxes of baseball cards in boxes of 30 and in boxes of 60. If she sells 5 boxes of 30, and 3 boxes of 60, how many baseball cards did she sell?


330 trading cards

400

7,000 x 4=

28,000

400

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

400

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 

400

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

$1,036

400

Maureen's team did a fund raiser to earn money for new uniforms. They raised $480. Maureen's team bought 9 uniforms that cost $45. How much money did they have left over?

$75

500

Jenna saved $100. She wants to buy 6 games that cost $20. Does she have enough money? Explain.

No, she needs 20 more dollars.

500

A city recycles 7,610 pounds of paper in one year. If they recycle the same amount each year, about how many pounds of paper will they recycle in 7 years?

56,000 pounds

500

The animal shelter charges $119 to adopt a pet. On Saturday 7 dogs and 2 cats were adopted. How much money did the animal shelter receive from these adoptions?

$1071

500

A grocery store orders 47 bags of onions and 162 bags of potatoes. The onions cost $2 per bag and the potatoes cost $3 per bag. How much money was spent on the onions and potatoes?

$580

500

At the math club ceremony, there were 17 tables with 9 people at each table. Each person received 2 certificates. How many certificates were distributed at the ceremony?

306 certificates