Show:
Estimation
Break Apart
Mental Math Masters
Word Problems
Multiplication
100
Estimate the following product. 457 X 9
About 450
100
What is 25 X 7
175
100

What is 100 x 30 ? 

3,000

100
Mr. Howard arranged his desks with five rows with seven desks in each row. How many desks does he have in the classroom?
35 desks.
100
89X6
534
200
Estimate the following product. 4,569 X 2
About 10,000
200
56 X 4
224
200

What is 9,000 x 6?

54,000

200
Erika wants to give 5 stickers to everyone in her class. Her class sits in 4 rows of 8. Erika says she needs 140 stickers. Is she correct? Why or why not?
She is incorrect. She actually needs 160 stickers. First I had to find the number of students that were in her class which is 32 students. Then I multiplied 32 by 5 to find the total number of stickers needed.
200
731 X 8
5,768
300
Estimate the following product. 57 X 9
540
300
78 X 4
312
300

What is 80 x 500 ? 

40,000

300
Marisa says 302 X 6 = 192. Is she correct? explain why her answer is reasonable or not reasonable.
She is incorrect. When I multiple 302 by 6 I got the final product of 1,812, which is much larger than 192.
300
321 X 9 = ?
2,889
400
Round to the nearest 10s place then estimate to solve. 123 X 5
600 (120 X 5)
400
99 X 9
891
400

Explain how to use mental math to solve:  50 x 250?  

Multiply 5 x 25 to get 125.  Then add back the two zeros to get 12,500

400
Jamie practiced his spanish skills for about 11 hours every week for 8 weeks About how many hours did he practice in all? How can you check your work? Is the estimation reasonable?
He practiced for about 80 hours in total. I found this by rounding to the nearest 10s place and then multiplied by 8 to get my estimation of 80. I can check my estimation by multiplying 8 by 11 which equals 88. My answer is reasonable because 80 is close to 88.
400
9 X 45
405
500

There are 52 weeks in a year.  If Joe turned 9 today, what is the best estimate for how many weeks he has been alive? 

A  600 weeks     B    540 weeks       C      530 weeks      D   450 weeks

D   450 weeks

500
76 X 8
608
500

A gallon of paint can cover about 400 square feet of wall space. About how many square feet will 3 gallons of paint cover?

1,200 square feet

500

There are 5 animals on a farm. Each animal eats 105 pounds of food per week. How much food does the farmer have to buy each week? Draw a model to help solve and explain your reasoning? How do you know if your answer is reasonable?

105 X 5 = 525. I found this answer by using the break apart method to find my partial products then I added my partial products to find my product. My answer is reasonable because when I round 105 to 110 and then multiple, I get the product of 550 which is close to 525. *You can also round down to 100 *Mr. Howard will check models

500
5432 X 2
10,864