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Relate problem
situations to number sentences involving addition
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and subtraction.
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HTXDWLRQVZLWKDV\PEROIRUWKHXQNQRZQQXPEHUWRUHSUHVHQWWKHSUREOHP
UNDERLYING SKILLS AND CONCEPTS:
concept of addition;
concept of subtraction
Choose a Number Sentence
Read word problems carefully.
a
K
ey Ide
You can draw a picture to show the problem.
Then you can choose a number sentence that matches.
E x am p l E
Don used 8 stickers.
Marie used 15 stickers.
How many more stickers did Marie use?
Which number sentence can you use to solve
the problem?
■
15 # 8 " ■
B – © CSL Associates, Inc. All rights reserved.
8 ! 15 "
Show the problem. Draw a picture.
?
8 stickers
15 stickers
7 stickers
Compare the number of stickers.
You can subtract.
So 15 # 8 " 7 solves the problem.
Marie used 7 more stickers than Don.
Chapter 12 – Lesson 4
page 141
Name
P RAC T I C E
Circle the number sentence that matches the story. Solve.
12 birds are in a tree.
5 fly away.
How many are left?
2
■
12 5 ■ 7
■ 17
98■
12 5 3
23 children are playing.
12 are sitting.
How many children are
there in all?
98
4
■ 35
23 12 ■
Carlita has 25 trucks.
Pat has 12 trucks.
How many more trucks
does Carlita have?
15 9 6
■
25 12 ■ 13
25 12 Math
Reasoning
7
15 bugs are in the grass. 9
bugs are on a leaf. How
many more bugs are in the
grass?
■
15 9 ■ 6
23 12 5
9 ducks are swimming.
8 ducks are eating.
How many are there?
Frank has 19 counters.
Ted has 17 counters.
How many counters do
they have in all?
■ 36
19 17 ■
19 17 Algebra
MR 1.1
What number makes the sentence true? Explain.
25 30 30 ■ 25; Possible answer: The
sentence is a turnaround fact.
page 142
Chapter 12 – Lesson 4
B – © CSL Associates, Inc. All rights reserved.
1
Name
P RAC T I C E
Circle the number sentence that matches the story. Solve.
15 ants are on a log.
6 ran away.
How many are left?
2
■
15 6 ■ 9
■ 30
21 9 ■
15 6 3
21 9 8 bunnies are hopping.
14 bunnies are sleeping.
How many bunnies are
there in all?
4
■ 22
14 8 ■
14 8 Ashley has 24 markers.
Phil has 18 markers.
How many markers do
they have altogether?
■ 42
24 18 ■
24 18 Math
Reasoning
7
14 birds are in the tree.
8 birds fly to the tree. How
many birds are there
altogether?
■ 22
14 8 ■
8 14 5
21 children are swimming.
9 children are eating.
How many are there?
6
Dan has 18 pennies.
John has 16 pennies.
How many pennies do they
have in all?
■ 34
18 16 ■
18 16 Algebra
MR 1.1
What number makes the sentence true? Explain.
35 40 ■ 5 40 30;
Write 35 as 3 tens and 5 ones.
page 96
Home Resource and Homework
Chapter 12 Lesson 4
B – © CSL Associates, Inc. All rights reserved.
1
MCX94TEG2Ch01_30.v9.4.1 2/19/01 19:48 Page 261
Name
P RAC T I C E
Circle the number sentence that matches the story. Solve.
1
12 birds are in a tree.
5 fly away.
How many are left?
2
■
12 5 ■ 7
■ 17
98■
12 5 3
98
23 children are playing.
12 are sitting.
How many children are
there in all?
4
■ 35
23 12 ■
B – © CSL Associates, Inc. All rights reserved.
15 9 Carlita has 25 trucks.
Pat has 12 trucks.
How many more trucks
does Carlita have?
6
■
25 12 ■ 13
7
Frank has 19 counters.
Ted has 17 counters.
How many counters do
they have in all?
■ 36
19 17 ■
25 12 Math
Reasoning
15 bugs are in the grass. 9
bugs are on a leaf. How
many more bugs are in the
grass?
■
15 9 ■ 6
23 12 5
9 ducks are swimming.
8 ducks are eating.
How many are there?
19 17 Algebra
MR 1.1
What number makes the sentence true? Explain.
25 30 30 ■ 25; possible answer: the
sentence is a turnaround fact.
Chapter 12 – Lesson 4
Student Book Page
page 142
Name
P RAC T I C E
Circle the number sentence that matches the story. Solve.
15 ants are on a log.
6 ran away.
How many are left?
2
■
15 6 ■ 9
■ 30
21 9 ■
15 6 3
21 9 8 bunnies are hopping.
14 bunnies are sleeping.
How many bunnies are
there in all?
4
■ 22
14 8 ■
14 8 Ashley has 24 markers.
Phil has 18 markers.
How many markers do
they have altogether?
■ 42
24 18 ■
24 18 Math
Reasoning
7
14 birds are in the tree.
8 birds fly to the tree. How
many birds are there
altogether?
■ 22
14 8 ■
8 14 5
21 children are swimming.
9 children are eating.
How many are there?
6
Dan has 18 pennies.
John has 16 pennies.
How many pennies do they
have in all?
■ 34
18 16 ■
18 16 Algebra
MR 1.1
What number makes the sentence true? Explain.
35 40 ■ 5 40 30;
Write 35 as 3 tens and 5 ones.
page 96
Home Resource and Homework
Chapter 12 Lesson 4
B – © CSL Associates, Inc. All rights reserved.
1