103 x 80 = ________
80,000
Estimate 91 x 54.
91 is close to 90
54 is close to 50
90 x 50 = 4,500
519 x 4 = ?
519 x 4 = 2,076
Find the product.
53 x 17 = ?
53 x 17 = 901
Find the product of 45 x 338.
45 x 338 = 15,210
Find the product.
406 x 53 = ?
406 x 53 = 21,518
What number would be equivalent to multiplying a number by 104?
multiplying by 10,000
Estimate 37 x 88.
37 is about 40
88 is about 90
40 x 90 = 3,600
Find the product.
768 x 8 = ?
768 x 8 = 6,144
Find the product.
41 x 23 = ?
41 x 23 = 943
What is the missing number?
7
Find the product.
709 x 41 = ?
709 x 41 = 29,069
Find 65 x 105.
6,500,000
Estimate 180 x 586.
180 is about 200
586 is about 600
200 x 600 = 120,000
Find the product.
249 x 4 = ?
249 x 4 = 996
Find the product.
89 x 27 = ?
89 x 27 = 2,403
Find the product.
946 x 33 = ?
946 x 33 = 31,218
Find the product.
24 x 104 = ?
24 x 104 = 2,496
Is the equation below correct or incorrect? Explain.
56 x 103 = 560
The equation is incorrect. The product should have 3 zeros, 56,000.
Estimate 7 x 396.
396 is about 400
I know that 7 x 4 = 28,
so 7 x 400 = 2,800
Find the product.
893 x 7 = ?
893 x 7 = 6,251
Find the product.
78 x 47 = ?
78 x 47 = 3,666
Abby is building a rectangular patio. The patio will be 108 bricks wide and 19 bricks long. How many bricks does she need to build the patio?
108 x 19 = 2,052 bricks
Find the product.
507 x 34 = ?
507 x 34 = 17,238
Select all the expressions that are equal to 3 x 103.
a) 3 x 1,000
b) 3 x 100
c) 30 x 100
d) 300 x 100
e) 300 x 10
These expressions are equal to 3 x 103:
a) 3 x 1,000
c) 30 x 100
e) 300 x 10
Lance has 102 packages of sports cards. Each package has 28 cards. Use rounding to estimate. About how many cards does Lance have?
About 3,000 cards.
102 is about 100
28 is about 30
100 x 30 = 3,000
Find the product.
1,278 x 4 = ?
1,278 x 4 = 5,112
Ten years ago, Melissa planted a tree in her backyard. She has taken a photo of the tree every week so she can see how it has grown as time passed. How many photos of the tree does Melissa now have?
Think: how many weeks are in one year?
10 x 52 = 520 photos
Is 3,198 a reasonable product for 727 x 44? Why or why not?
No. The answer should be much greater than 3,198. If I estimate 7 x 4 = 28, so 700 x 40 would be about 28,000 - which is not close to 3,198.
*The actual product would be 31,988.
There are 36 large fish tanks at the zoo. Each tank holds 205 gallons of water. How many gallons of water would it take to fill all of the tanks?
205 x 36 = 7,380 gallons of water