CCSS
Fluently
and subtract
within
1000numbers
using strategies and
NS 2.1G3.NBT.2
Find the sum
or add
difference
of two
whole
algorithms based on place value, properties of operations, and/or the relationship
between 0 and 10,000.
between addition and subtraction.
UNDERLYING SKILLS AND CONCEPTS:
subtraction basic facts; regroup
tens and ones; regroup hundreds
and tens; place value
Subtract 3-Digit Numbers
You can use place value and basic facts to
subtract three-digit numbers.
a
K
ey Ide
To check your answer, add the difference back to the
number you subtracted. You should get the first number in
the problem.
E x am p l E
Calvin wrote a 350-word story and a 187-word book report.
How many more words were in the story than in the book report?
Find 350 187. You can use place value and regrouping.
Step 2: To subtract tens,
Step 3: Subtract hundreds.
you need to regroup a hundred. 4 10
3 5 0
1 8 7
3
2 14 10
2 14 10
10
7
3
3 5 0
1 8 7
6 3
140
14
so
80
8
60
6
3 5 0
200
1
8
7
100
100
1 6 3
You can use the block model to check.
Step 1: Regroup 10 to ones.
300 40 10
The story was 163 words longer.
page 86
Step 2: Regroup 100 to 10 tens.
200 10
140
Step 3: Subtract 187.
100 60
3
Chapter 8 – Lesson 1
C – © CSL Associates, Inc. All rights reserved.
Step 1: To subtract ones,
you need to regroup a ten.
Name
P RAC T I C E
Subtract.
1. 218
129
2.
251
142
89
6.
175
119
109
7.
112
108
8.
70
12.
365
335
4
325
199
4.
126
325
255
56
11.
3.
450
229
249
151
30
5.
285
9.
221
13.
411
126
525
280
97
10.
245
14.
98
599
511
88
247
150
675
225
450
15.
432
348
84
C – © CSL Associates, Inc. All rights reserved.
Solve.
16. Cindy counted the words in her
storybook. On one page there
were 250 words. On the next
page there were 178 words. How
many words did Cindy count?
250 178 428 words
Math
Reasoning
17. Lao found out that the letter e is
used more often than any other
letter of the alphabet. In one
paragraph he counted 540
letters. 86 of them were e. How
many letters were NOT e?
540 86 454 letters
Number Sense
MR 1.1
18. The difference of two numbers is 333.
What are the two largest three-digit numbers
that give this difference?
What are the smallest three-digit numbers that give this difference?
999 666 333
433 100 333
Chapter 8 – Lesson 1
page 87
MCX94.HW.CL.G3.FM&Lesson.v211
8/3/04
13:56
Page 58
Name
…at home!
P RAC T I C E
Subtract.
1. 316
227
2.
89
6.
198
129
118
109
9
3.
118
7.
69
11.
262
144
455
385
245
225
4.
423
136
178
8.
70
12.
365
187
560
338
287
9.
423
195
222
13.
328
299
20
5.
74
10.
228
14.
477
422
29
55
234
160
765
305
460
15.
321
236
85
16. Tammy counted the words in
her storybook. On one page
there were 250 words. On the
next page there were 185 words.
How many words did Tammy
count?
250 185 435 words
Math
Reasoning
17. Sean found out that the letter e
is used more often than any
other letter of the alphabet. In
one paragraph he counted 480
letters. 72 of them were e. How
many letters were NOT e?
480 72 408 letters
Number Sense
MR 1.1
18. The difference of two numbers is 444.
What are the two largest three-digit numbers
that give this difference?
What are the smallest three-digit numbers that give this difference?
999 555 444
544 100 444
page 58
Home Resource and Homework
Chapter 8 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
Solve.
MCX94TEG3Ch01_32.v8.9.3 2/21/01 14:45 Page 161
Name
P RAC T I C E
Subtract.
1. 218
129
2.
251
142
89
6.
175
119
109
7.
112
108
8.
70
12.
365
335
4
325
199
4.
126
325
255
56
11.
3.
450
229
249
151
30
5.
285
9.
221
13.
411
126
525
280
97
10.
245
14.
98
599
511
88
247
150
675
225
450
15.
432
348
84
C – © CSL Associates, Inc. All rights reserved.
Solve.
16. Cindy counted the words in her
storybook. On one page there
were 250 words. On the next
page there were 178 words. How
many words did Cindy count?
250 178 428 words
Math
Reasoning
17. Lao found out that the letter e is
used more often than any other
letter of the alphabet. In one
paragraph he counted 540
letters. 86 of them were e. How
many letters were NOT e?
540 86 454 letters
Number Sense
MR 1.1
18. The difference of two numbers is 333.
What are the two largest three-digit numbers
that give this difference?
What are the smallest three-digit numbers that give this difference?
999 666 333
433 100 333
Chapter 8 – Lesson 1
Student Book Page
page 87
Name
…at home!
P RAC T I C E
Subtract.
1. 316
227
2.
89
6.
198
129
118
109
9
3.
118
7.
69
11.
262
144
455
385
245
225
4.
423
136
178
8.
70
12.
365
187
560
338
287
9.
423
195
222
13.
328
299
20
5.
74
10.
228
14.
477
422
29
55
234
160
765
305
460
15.
321
236
85
16. Tammy counted the words in
her storybook. On one page
there were 250 words. On the
next page there were 185 words.
How many words did Tammy
count?
250 185 435 words
Math
Reasoning
17. Sean found out that the letter e
is used more often than any
other letter of the alphabet. In
one paragraph he counted 480
letters. 72 of them were e. How
many letters were NOT e?
480 72 408 letters
Number Sense
MR 1.1
18. The difference of two numbers is 444.
What are the two largest three-digit numbers
that give this difference?
What are the smallest three-digit numbers that give this difference?
999 555 444
544 100 444
page 58
Home Resource and Homework
Chapter 8 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
Solve.