&&66
)OXHQWO\DGGDQGVXEWUDFWZLWKLQXVLQJVWUDWHJLHVEDVHGRQ
NS 2.6*1%7
Solve addition
and subtraction problems with one- and two-digit
SODFHYDOXHSURSHUWLHVRIRSHUDWLRQVDQGRUWKHUHODWLRQVKLSEHWZHHQDGGLWLRQDQG
VXEWUDFWLRQnumbers (e.g., 5 ! 58 " __).
UNDERLYING SKILLS AND CONCEPTS:
basic facts;
grouping ten and extras;
mental math
Subtract 1-Digit from 2-Digit Numbers
a
K
ey Ide
You can use ten-frames and counters to help
subtract from large numbers.
E x am p l E
Pat had 34 carrots in his garden.
He picked 6 carrots.
How many carrots are left in the garden?
Find
34
# 6
Model 34.
A – © CSL Associates, Inc. All rights reserved.
Take away the 6 he picked.
Count how many are left.
Pat has 28 carrots left in the garden.
Chapter 20 – Lesson 3
page 235
Name
P RAC T I C E
Subtract.
1
49 6 43
2
37 9 28
3
24 3 21
4
35 9 26
5
56 7 49
6
42 4 38
7
29 8 21
8
46 5 41
9
55 4 51
14
25
33
12
36
13
21
9
9
9
9
16
24
27
12
32
15
45
16
29
17
38
5
6
8
5
27
39
21
33
Math
Reasoning
18
11
Number Sense
MR 1.1
Ronnie used to have 43 tomatoes in his garden.
He picked some.
Now he has 34 tomatoes.
How many tomatoes did Ronnie pick?
Explain.
9 tomatoes. You can subtract 9 from 43 to get 34.
page 236
Chapter 20 – Lesson 3
A – © CSL Associates, Inc. All rights reserved.
10
Name
…at home!
P RAC T I C E
Subtract.
1
39 8 31
2
36 5 31
3
22 4 18
4
25 6 19
5
48 9 39
6
41 6 35
7
49 9 40
8
55 7 48
9
56 5 51
14
28
32
12
37
13
31
9
8
8
9
19
24
29
22
33
15
34
16
39
17
47
5
6
8
5
28
28
31
42
Math
Reasoning
18
11
Number Sense
MR 1.1
Doug used to have 32 radishes in his garden.
He picked some.
Now he has 23 radishes.
How many radishes did Doug pick?
Explain.
9 radishes. You can subtract 9 from 32 to get 23.
page 158
Home Resource and Homework
Chapter 20 Lesson 3
A – © CSL Associates, Inc. All rights reserved.
10
MCX94TEG1Ch01_30.v8.4.1 2/19/01 19:24 Page 433
Name
P RAC T I C E
Subtract.
1
49 6 43
2
37 9 28
3
24 3 21
4
35 9 26
5
56 7 49
6
42 4 38
7
29 8 21
8
46 5 41
9
55 4 51
A – © CSL Associates, Inc. All rights reserved.
10
14
25
33
36
12
13
21
9
9
9
9
16
24
27
12
32
15
45
29
16
17
38
5
6
8
5
27
39
21
33
Math
Reasoning
18
11
Number Sense
MR 1.1
Ronnie used to have 43 tomatoes in his garden.
He picked some.
Now he has 34 tomatoes.
How many tomatoes did Ronnie pick?
Explain.
9 tomatoes. You can subtract 9 from 43 to get 34.
Chapter 20 – Lesson 3
Student Book Page
page 236
Name
…at home!
P RAC T I C E
Subtract.
1
39 8 31
2
36 5 31
3
22 4 18
4
25 6 19
5
48 9 39
6
41 6 35
7
49 9 40
8
55 7 48
9
56 5 51
14
28
32
12
37
13
31
9
8
8
9
19
24
29
22
33
15
34
16
39
17
47
5
6
8
5
28
28
31
42
Math
Reasoning
18
11
Number Sense
MR 1.1
Doug used to have 32 radishes in his garden.
He picked some.
Now he has 23 radishes.
How many radishes did Doug pick?
Explain.
9 radishes. You can subtract 9 from 32 to get 23.
page 158
Home Resource and Homework
Chapter 20 Lesson 3
A – © CSL Associates, Inc. All rights reserved.
10