Download Multiply Across Zero - MathCoach Interactive

CCSS
Multiply
a whole number
of up
to four digits byofamulti–digit
one-digit whole
NS 2.4G4.NBT.5
Solve simple
problems
involving
multiplication
number, and multiply two two-digit numbers, using strategies based on place value and
numbers
by one-digit
3 ___).
the properties
of operations.
Illustrate numbers
and explain(3,671
the calculation
by using equations,
rectangular arrays, and/or area models.
UNDERLYING SKILLS AND CONCEPTS:
multiplication as repeated
addition
Multiply Across Zero
You can use basic facts and place value
to multiply larger numbers.
a
K
ey Ide
E x am p l E
Find the product of 2,042 4.
One way: Write 2,042 in expanded notation.
2,042 2,000 40 2
Multiply each part by 4.
(2,000 4) + (40 4) (2 4)
160
8,168
8
Another way: You can use place value and regrouping.
Step 1: Multiply the ones by 4.
428
s
and dredss
s
u
es
n
Tho Hu Ten On
Step 2: Multiply the tens by 4.
4 40 160
Record the tens.
Regroup the hundreds.
1
2, 0 4 2
4
Step 3: Record the hundreds.
Record regrouping here.
Multiply in each place value.
Add the regrouped digits.
8, 1 6 8
Step 4: Multiply the thousands by 4.
4 2,000 8,000
Record the thousands.
page 136
Chapter 12 – Lesson 2
C – © CSL Associates, Inc. All rights reserved.
8,000
Name
P RAC T I C E
Use expanded notation to multiply.
1. 407 5
( 400 5) ( 7
5)
( 700 6) ( 3
2,000 + _______
35 = _______
2,035
_______
3. 806 3
3)
4,200 + _______
18 = _______
4,218
_______
( 500 7) ( 8
2,400 + _______
18 = _______
2,418
_______
5.
3, 0 2 5
8
Math
Reasoning
7)
3,500 + _______
56 = _______
3,556
_______
6.
6)
4. 508 7
( 800 3) ( 6
C – © CSL Associates, Inc. All rights reserved.
2. 703 6
7.
2, 7 0 4
6
Number Sense
7, 0 0 6
4
MR 3.2
8. How is multiplying 45 3 like multiplying 405 3?
How is it different?
Same: I use the same basic facts.
Different: 45 x 3 = 135 and 405 x 3 = 1,215.
Chapter 12 – Lesson 2
page 137
MCX94.HW.CL.G3.FM&Lesson.v211
8/3/04
13:56
Page 92
Name
…at home!
P RAC T I C E
Multiply.
1. 308 4
2. 804 6
( 300 4) ( 80 4)
( 800 6) ( 40 6)
1,200 + _______
32 = _______
1,232
_______
3. 507 7
4,800 + _______
24 = _______
4,824
_______
4. 603 3
( 500 7) ( 70 7)
( 600 3) ( 30 3)
3,500 + _______
49 = _______
3,549
_______
6.
4, 2 0 6
7
Math
Reasoning
7.
3, 0 8 4
7
5, 0 0 6
5
Number Sense
MR 3.2
8. How is multiplying 65 x 4 like multiplying 605 x 4?
How is it different?
Same: I use the same basic facts.
Different: 65 4 260 and 605 4 2,420.
page 92
Home Resource and Homework
Chapter 12 Lesson 2
C – © CSL Associates, Inc. All rights reserved.
5.
1,800 + _______
9
= _______
1,809
_______
MCX94TEG3Ch01_32.v8.9.3 2/21/01 14:46 Page 253
Name
P RAC T I C E
Use expanded notation to multiply.
1. 407 5
( 400 5) ( 7
5)
2. 703 6
( 700 6) ( 3
2,000 + _______
35 = _______
2,035
_______
3. 806 3
4,200 + _______
18 = _______
4,218
_______
4. 508 7
( 800 3) ( 6
3)
( 500 7) ( 8
2,400 + _______
18 = _______
2,418
_______
C – © CSL Associates, Inc. All rights reserved.
5.
2
6)
6.
2 4
3, 0 2 5
8
2 4, 2 0 0
Math
Reasoning
1 4
3,500 + _______
56 = _______
3,556
_______
2
2, 7 0 4
6
7)
7.
2
7, 0 0 6
4
1 6, 2 2 4
2
2 8, 0 2 4
Number Sense
MR 3.2
8. How is multiplying 45 3 like multiplying 405 3?
How is it different?
Same: I use the same basic facts.
Different: 45 x 3 = 135 and 405 x 3 = 1,215.
Chapter 12 – Lesson 2
Student Book Page
page 137
Name
…at home!
P RAC T I C E
Multiply.
1. 308 4
2. 804 6
( 300 4) ( 80 4)
( 800 6) ( 40 6)
1,200 + _______
32 = _______
1,232
_______
3. 507 7
4,800 + _______
24 = _______
4,824
_______
4. 603 3
( 600 3) ( 30 3)
3,500 + _______
49 = _______
3,549
_______
5.
2 1
6.
4
4, 2 0 6
7
2 9, 4 4 2
Math
Reasoning
2
1,800 + _______
9
= _______
1,809
_______
5 2
3, 0 8 4
7
7.
3
2
5, 0 0 6
5
2 1, 5 8 8
2 5, 0 3 0
Number Sense
MR 3.2
8. How is multiplying 65 x 4 like multiplying 605 x 4?
How is it different?
Same: I use the same basic facts.
Different: 65 4 260 and 605 4 2,420.
page 92
Home Resource and Homework
Chapter 12 Lesson 2
C – © CSL Associates, Inc. All rights reserved.
( 500 7) ( 70 7)