Estimate
Estimate the product.
23 x 11 =
23 x 11 =
20 x 10 =
(2 x 10) x (1 x 10) =
2 x 100 = 200
Use partial products.
27 x 2 =
27
x 2
14
+ 40
54
Use the area model.
6 x 108 =
Whiteboard work :)
Answer: 648
Estimate the product.
73 x 84 =
73 x 84 =
70 x 80 =
(7 x 10) x (8 x 10) =
56 x 100 = 5600
Use partial products.
27 x 12 =
x 12
14
40
+ 70
200
324
Use the area model.
35 x 24 =
Whiteboard work :)
Answer: 840
Estimate the product.
53 x 42 =
53 x 42 =
50 x 40 =
(5 x 10) x (4 x 10) =
20 x 100 =
2 x 10 x 100 =
2 x 1000 = 2000
Use partial products.
42 x 38 =
42
x 38
16
320
+ 60
1200
Use the area model.
42 x 38 =
Whiteboard work :)
Answer: 1,596
Estimate. Determine whether the estimate is GREATER THAN or LESS THAN the actual product.
94 x 82 =
94 x 82 =
90 x 80 =
(9 x 10) x (8 x 10) =
72 x 100 = 7200
LESS THAN BECAUSE YOU ROUNDED DOWN!
Use partial products.
91 x 78 =
91
x78
8
720
+ 70
6300
7098
Use the area model.
64 x 46 =
Whiteboard work :)
Answer: 2,944
Mrs. Green and Ms. Trinh spend 15 hours each week planning lessons for their wonderful students. There are 52 weeks in one year. About how many hours do these cool teachers spend planning in one year?
15 x 52 =
20 x 50 =
(2 x 10) x (5 x 10) =
10 x 100 = 1000
Mrs. Green and Ms. Trinh spend about 1000 hours planning lessons each year.
Use partial products.
Messi can kick a distance of 40 yards. How many yards would it be if Messi kicked a ball 22 times?
40
x 22
0
80
+ 0
800
880
Messi can kick the ball 880 yards if he kicked it 22 times.
Use the area model.
Room 10 students received an award if they finished 45 minutes of iReady lessons each week. Room 10 won 25 awards for completing their goals. How many minutes did Room 10 students learn in total?
Whiteboard work :)
Answer: 1,125