Estimates
30x50
The answer to a multiplication problem.
What would be the partial products of 1,421 x 3? DON'T SOLVE.
1,000 x 3
400 x 3
20 x 3
1 x3
Solve using the TRIANGLE trick: 1,000 x 400=
400,000
The product of two factors is 1,200. One of the factors is 20. What is the other factor?
A) 40
B) 120
C) 60
D) 600
C) 60
Round 68 to the nearest 10.
70
A factor is...
Numbers that multiply together to get a product.
Solve using partial products: 53 x4
50 x 4 = 200
3 x 4 = 12
53 x4 = 212
Solve using area model 64 x 4 =
256
Mr. Luca bought 28 notebooks. Each notebook has 54 pages. What is a good way to estimate the total number of pages Mr. Luca bought?
A) 20 x 50
B) 30 x 50
C) 28 x 60
B) 30 x 50
Estimate the product of 82 x 71
80 x 70 =5,600
An estimate is...
A number that is CLOSE to the actual number.
Solve using partial products: 452 x 6
400 x 6 = 2,400
50 x 6 = 300
2 x 6= 12
2,400 + 300 + 12 = 2,712
Solve using area model: 1,563 x 7 =
10,941
George swam 14 laps 12 times in may. He sawm 15 lap 16 times in June. How many laps did George swim in total?
George swam 408 laps in total.
Andrew says that the correct estimate for 67x33 would be 70 x 40. Is Andrew correct? If not, what is the correct estimate?
70 x 30 = 2,100
An equation is...
A math sentence with an equal sign.
Solve using partial products: 1,456 x 4
1,000 x 4 = 4,000
400 x 4 = 1,600
50 x 4 = 200
4 x 4 = 16
4,000 + 1,600 + 200 + 16 = 5,824
Solve using area model: 33 x 54=
1,782
A bakery has 12 bins of bagels. Each bin is filled with 37 bagels. How many bagels are there all together?
37 x 12 = 444
Mr. B is buying 3 books. Each book costs 48 dollars. Mr. B thinks the cost should be about 150 dollars. Is Mr. B correct? Explain your thinking.
Yes, Mr. B is correct because 48 rounds to 50 and 50x3= 150.
A variable is...
A letter that stands for an unknown number.
What answer choices include the partial products for 63 x4? Choose all that apply.
A) 60
B) 30
c) 3
D) 4
E) 252
A) 60
B) 3
D) 4
E) 252
Solve using area model: 86 x 37 =
3,182
One wall in 4A is 27 feet long. The other wall is 18 feet long. What is the area of 4A?
27 x 18 = 486