Multiply by 10's,100's and 1000's
Estimate the Product
Use array's and partial products
Area Model
Math Riddles
100

Give me the values for all 3.

8 x 20

8 x 200

8 x 2,000

Answer: 160, 1,600 and 16,000

100
Estimate the product


6 x 1,310

Answer:

6,000

100

What is the answer for this question?

3 rows, 1 ten in each row

3 rows, 3 ones in each row

Answer: 39

100

Using the area model, what is the partial products for 34 x 6?

Answer: 180 and 24
100

How do you make the number 7 an even number without addition, subtraction, multiplication, or division?

Answer: Take out the "S"

200

Give the value for all 3. 

5 x 70

5 x 700

5 x 7,000

Answer: 350, 3,500 and 35,000

200

Estimate the product


9 x 62

Answer:

540

200

Find 2 x 105 using arrays.

2 rows, 1 hundred in each row

2 rows, 5 ones in each row

Answer: 210

200

Using the area model, what would the partial products be for 3 x 185?

Answer: 300, 240 and 15

200

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Answer: The person was born in 1990 bce. 

300

What is the value of this problem?

8 x 7,000

Answer: 56,000

300

Estimate the product


9 x 4,720

Answer:

9 x 5,000 = 45,000

300

Find the answer for 2 x 411 by using arrays.

2 rows, 4 hundred in each row

2 rows, 1 ten in each row

2 rows, 1 one in each row

Answer: 822

300

Wyatt said he used partial products to write 7 x 870 = 5,600 + 49. What was Wyatt's error? Fix his work

Answer: Yes.  He should have done 800 x 7 and 70 x 7.  He should have gotten 5,600 + 490

300

How many times can you subtract the number 5 from 25

Answer: Once. After that you will be subtracting 5 from 20

400

What is the value of this problem?

8,000 x 6

Answer: 48,000

400

Find out if this answer is reasonable.  Jack says that the estimated product for 5 x 1,879 is 2,573. Is he correct?

Answer: No, the estimated product would be 5 x 2,000 which is 10,000.  Jacks estimated answer isn't close to 10,000

400

Find the answer using arrays. 3 x 316

3 rows, 3 hundreds in each row

3 rows, 1 ten in each row

3 rows, 6 ones in each row

Answer: 948

400

Using the Area Model, find the answer to:

3,450 x 4

Answer: 13,800

12,000 + 1,600 + 200.

400

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again

Answer: 50/50

500
Jeremy has 7 sheets of stickers.  Gary has 4 sheets of stickers.  If each sheet of stickers contains 40 stickers, how many stickers do the 2 boys have?

Answer: 280 + 160 = 440

500

Tell me if the estimated product is reasonable.  Mary says that 7 x 289 will equal 2,023.  Is Mary correct?

Explain

Answer: Yes.  The estimated product would be 7 x 300 which would equal 2,100 which is close to 2,023

500

Write down all the expressions that have a value of 464.

a. 400 x 64

b. (4 x 100) + 16

c. 4 x 116

d. 4 x (400 + 60 + 4)

e. (4 x 100) + (4 x 10) + (4 x 8)

Answer: Choices C and E

500
Using the Area Model, find the product of:


4,265 x 5

Answer: 21,325

20,000 + 1,000 + 300 + 25

500

 There is a clothing store in San Jose. The owner has devised his own method of pricing items. A vest costs $20, socks cost $25, a tie costs $15 and a blouse costs $30. Using this pattern, how much would a pair of underwear cost?

Answer: 45 dollars. The store owner is charging 5 dollars per letter in the item.

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