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Date:
H A PTE
R
C
Name:
8
Addition and Subtraction
Facts to 20
PROBLEM SOLVING
Thinking Skills
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
1.
Fill in the blanks with 14, 13, and 7.
a.
−
+
= 20
b.
+
–
=6
Solve.
Show your work.
2.
16 children are in a line.
7 children leave the line.
4 children join the line.
How many children are in the line now?
children are in the line now.
Enrichment 1A
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Name:
Date:
Solve.
Show your work.
3.
2+3+4+5+6=
4.
Find the value of
+
.
+
= 18
+
= 11
The value of
60
is
.
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
=
Chapter 8 Addition and Subtraction Facts to 20
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Name:
Date:
PROBLEM SOLVING
Strategies
Solve.
Show your work.
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
5.
Jill has some cards.
She gives Ben 9 cards.
She gives Kelly 4 cards.
Jill has 2 cards left.
How many cards did Jill have at first?
Jill had
6.
cards at first.
Greg thinks of two numbers.
When he adds them, he gets 17.
When he subtracts one from the
other, he gets 9.
What are the two numbers?
The two numbers are
and
A + B = 17
A–B=9
What can A
and B be?
.
Enrichment 1A
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Name:
Ken buys a pack of pens.
He gives 8 pens to Josh.
Ken gives 3 pens to Gillian.
Ken finds 6 more pens.
Now Ken has 10 pens.
How many pens did Ken buy at first?
Ken bought
62
pens at first.
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
7.
Date:
Chapter 8 Addition and Subtraction Facts to 20
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Name:
Date:
PROBLEM SOLVING
Exploration
Solve.
8.
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
9.
Write the number sentences.
Use three different numbers
from 5 to 15.
There is more
than one correct
answer.
+
–
= 12
–
+
= 12
Add 9 and 6.
Show three ways.
Use number bonds to help you.
9+6=
10.
Subtract 7 from 15.
Show two ways.
Use number bonds to help you.
15 – 7 =
Enrichment 1A
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Name:
Date:
Journal Writing
Write stories.
Write one addition story and one subtraction story.
Use the numbers and words.
5
64
9
Brad
Sue
apples
buys
16
a.
Addition story
b.
Subtraction story
sold
how many
more than
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
11.
Chapter 8 Addition and Subtraction Facts to 20
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Name:
Date:
© 2009 Marshall Cavendish International (Singapore) Private Limited. Copying is permitted; see page ii.
Look at the problems Jack completed.
Find his mistakes.
Explain the mistakes Jack made.
Then solve the problems correctly.
12.
9
-6
15
13.
14
-8
14
Enrichment 1A
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