Estimating
Estimate the product.
239 x 689 =
200 x 700 = 140,000
Round 345.67 to the nearest tenth.
345.7
If 456 x 23 = 10,488 what does 45.6 x 23 equal?
1,048.8
Solve using the standard algorithm.
45 x 23
1,035
2.2 x 45
99
Estimate the product.
762 x 58 =
800 x 60 = 48,000
Round 2,367.894 to the nearest hundredth.
2,367.89
If 894 x 213 = 190,422 what does 8.94 x 213 equal?
1,904.22
Solve using the area model.
233 x 125
29,125
6.3 x 124
781.2
Estimate the product.
429 x 489 =
400 x 500 = 200,000
Round 10,342.339 to the nearest hundredth.
10,342.34
If 56.4 x 23 = 1,297.2 what does 564 x 23 equal?
12,972
Solve using either the area model or the standard algorithm.
765 x 24
18,360
Mrs. Stark wants to buy pencil pouches for each of her 24 students. Each pencil pouch costs $2.98. She has $70. Does she have enough money? If not, how much more money does she need?
She does not have enough money. She needs $1.52.
Estimate the product.
24 x 99 =
20 x 100 = 2,000
Round 34,567.23 to the nearest thousand.
35,000
If 8.21 x 543 = 4,458.03 what does 821 x 543 equal?
445,803
Estimate the product and then solve.
328 x 77
300 x 80 = 24,000
328 x 77 = 25,256
23.68 x 245
5,801.60
Estimate the product and then find the actual product.
34 x 58 =
30 x 60 = 1,800
34 x 58 = 1,972
Round 986,362.785 to the nearest ten thousand.
990,000
If 987 x 34 = 33,558 what does 9.87 x 34 equal?
335.58
Mrs. Benson wants to buy a dozen donuts for each of her 25 students. How many donuts will she need?
12 x 25 = 300 donuts
Round to estimate. Then find the actual product.
322 x 4.77
300 x 5 = 1,500
322 x 4.77 = 1,535.94