Multiply It!
34 x 3 = ?
102
Use expanded form to solve:
4 x 23
(4 x 20) + (4 x 3)
80 + 12 = 92
Estimate:
48 x 6
50 x 6 = 300
A student says:
32 x 4 = 88
Is the student correct? Explain.
No. 32 x 4 = 128
A school has 6 boxes of pencils. Each box contains 24 pencils.
How many pencils are there altogether?
144 pencils
216 x 4 = ?
864
Use partial products to solve:
6 x 134
600 + 180 + 24 = 804
Estimate:
197 x 4
200 x 4 = 800
A student solves:
214 x 3 = 600 + 42 = 642
What did the student forget?
200 x 3 = 600 and 14 x 3 = 42, so the students is correct.
The school orders 4 packs of paper. Each pack has 325 sheets.
How many sheets of paper are ordered?
1,300 sheets
1,203 x 5 = ?
6,015
Use the distributive property to solve:
7 x 48
7 x (40 + 8)
280 + 56 = 336
Estimate:
3,912 x 3
4,000 x 3 = 12,000
A student solves:
306 x 4 =
(300 x 4) + (6 x 4)
1,200 + 24 = 1,224
Correct or incorrect?
Correct!
A field trip has 7 buses. Each bus can carry 48 students.
What is the maximum number of students the buses can carry?
336 students
2,406 x 7 = ?
16,842
Which strategy would YOU use to solve 8 x 2,103?
Explain WHY, then SOLVE it.
2,103 x 8 = 16,824
Bonus: If you can explain WHY your strategy works, +100 points.
Which answer is reasonable for 598 x 7?
A. 418
B. 4,186
C. 41,860
D. 418,600
B. 4,186
Bonus: How did you know without solving it exactly, +100 points.
A student solves:
2,105 x 6 = 12,630
Is the answer reasonable? Explain how you know.
Yes. 2,105 x 6 is about 2,000 x 6 = 12,000, so 12, 630 is reasonable.
The school is preparing for a festival. There are 8 tables. Each table needs 125 cups.
How many cups are needed altogether?
1,000 cups
1,943 x 3 = ?
5,829
Use the associative property to solve:
7 x 25 x 4
7 x 25 x 4 = 7 x (25 x 4)
7 x (100)
700
What two estimates is the product between?
6 x 437
2,400 and 3,000
Bonus: Why is it between these two numbers, +100 points.
A school orders 6 boxes of books. Each box contains 1,248 books.
1. Estimate the product.
2. Find the exact product.
3. Explain how you know your answer is reasonable.
Estimate: 1,248 to 1,200
1,200 x 6 = 7,200
Exact: 1,248 x 6 = 7,488
7,488 is reasonably close to 7,200.