homework_remembering_te_grade_4-1zwawpi

2-5
Name
Date
Estimate each sum. Then solve to check
your estimate. Estimates may vary.
1. 288 + 609
estimate: 300 + 600 = 900; exact: 897
Solve.
Estimates may vary.
2. During one weekend, a museum had 7,850 visitors on
Saturday and 5,759 visitors on Sunday.
Show your work.
About how many visitors were there that weekend?
8,000 + 6,000; about 14,000 visitors
Exactly how many visitors were there that weekend?
13,609 visitors
Draw a rectangle model. Find the tens product, the ones
product, and the total product.
3. 7 × 42 4. 5 × 67
7
40
+ 2
7 × 40 = 280 7 × 2 = 14
5
60
+ 7
5 × 60 = 300 5 × 7 = 35
280
+ 14 __
294
5. Stretch Your Thinking Marcia says she can use rounding
to find the exact product of 6 × 75. She says that since
75 is halfway between 7 tens and 8 tens, the exact
product of 6 × 75 must be halfway between The way students
6 × 70 and 6 × 80. Is she correct? Explain. show the work may vary.
6 × 70 = 6 × 7 × 10 6 × 80 = 6 × 8 × 10
= 42 × 10 = 48 × 10
= 420 = 480
Halfway between 420 and 480 is 450. The product
of 6 × 75 is the tens product 6 × 70 plus the
300
+ 35 __
335
ones product 6 × 5, which is 450. So, Marcia is correct.
© Houghton Mifflin Harcourt Publishing Company
38 UNIT 2 LESSON 5 Estimate Products