Download Multiply with Regrouping

Name
LESSON
43
1
Multiply with Regrouping
4.4.D
OBJECTIVE Use regrouping to multiply 2-digit numbers.
Estimate. Then use regrouping to find 28 × 43.
30 × 40 = 1,200
Step 1 Round to estimate the
product.
Step 2 Think: 28 = 2 tens 8 ones.
Multiply 43 by 8 ones.
8 × 3 = 24. Record the 4.
Write the regrouped 2 above
the tens place. 8 × 40 = 320.
Add the regrouped tens:
320 + 20 = 340.
2
43
×
28
_
344
Step 3 Multiply 43 by 2 tens.
20 × 3 = 60 and 20 × 40 = 800.
Record 860 below 344.
Step 4 Add the partial products.
8 × 43
2
43
×
28
_
344
+860
_
1,204
20 × 43
344 + 860
So, 28 × 43 = 1,204 . 1,204 is close to
1,200. The answer is reasonable.
© Houghton Mifflin Harcourt Publishing Company
Estimate. Then find the product.
1. Estimate:
36
×
12
_
Number and Operations
2. Estimate:
43
×
29
_
3. Estimate:
51
×
47
_
85
Name
1
Multiply with Regrouping
4.4.D
Estimate. Then find the product.
1. Estimate:
2,700
2
1
Think: 32 is close to 30 and 87 is close to 90.
30 × 90 = 2,700
87
× 32
_
174
+
2,610
__
2,784
73
× 28
_
5. Estimate:
84
×
40
_
3. Estimate:
48
× 38
_
6. Estimate:
83
×
77
_
4. Estimate:
59
× 52
_
7. Estimate:
91
×
19
_
Problem Solving
8. Baseballs come in cartons of
84 baseballs. A team orders
18 cartons of baseballs. How many
baseballs does the team order?
86
9. There are 16 tables in the school
lunch room. Each table can
seat 22 students. How many
students can be seated at lunch
at one time?
Lesson 43
© Houghton Mifflin Harcourt Publishing Company
2. Estimate: