Transcript Multiply Three-Digit Numbers

Five-Minute Check (over Lesson 3–5)
Main Idea
Example 1: Multiply Two-Digit Numbers
Example 2: Multiply Three-Digit Numbers
• I will multiply up to a three-digit number by a
two-digit number.
Multiply Two-Digit Numbers
The fastest human runner was clocked at
11 feet per second. How far will the runner
run in 55 seconds?
Estimate 55 × 11
55 × 10 = 550
Step 1
Step 2
Multiply the ones.
Multiply the tens.
×
55
11
5555
× 1 = 55
×
55
11
5555
× 10 = 550
550
Multiply Two-Digit Numbers
Step 3
Add.
×
+
55
11
55
55 + 550
550 = 605
605
Answer: So, the runner will run 605 feet in 55 seconds.
Find 13 × 32.
A. 65
B. 390
C. 410
D. 416
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B
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4.
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C
A
B
C
D
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D
Multiply Three-Digit Numbers
Find 438 × 46.
Estimate 438 × 46
400 × 50 = 20,000
Step 1
Step 2
Multiply the ones.
Multiply the tens.
438
438
×
46
2628
438 × 6 =
2,628
×
Step 3
46
Add.
×
2628
+
438 × 40 17520
= 17,520
Answer: So, 438 × 46 = 20,148.
438
46
2,628 + 2628
17,520 = 17
20,148
20
Find 723 × 21.
A. 15,183
B. 15,283
C. 16,197
D. 16,225
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A
B
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2.
3.
4.
0%
C
A
B
C
D
0%
D
End of the Lesson
Five-Minute Check (over Lesson 3–5)
Image Bank
Math Tool Chest
Multiply Mentally
(over Lesson 3–5)
Draw a picture to solve.
Vanita has a piece of fabric that is 54 inches wide
and two yards long. To make a headband, she
needs 3 strips that are each 18 inches long and 3
inches wide. What is the largest number of
headbands she can make from the fabric?
A. 16 headbands
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D
A
B
C
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C
D. 27 headbands
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A
C. 24 headbands
1.
2.
3.
4.
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B
B. 20 headbands