Grade K, Module 8
Core Focus
•
•
•
•
•
Introducing the addition symbol (+)
Using the commutative (turnaround) property for addition
Introducing the “think big, count small” idea
Identifying two parts that total 10
Identifying and using 3D objects and sorting 2D shapes and 3D objects
Addition
Ideas for Home
• Students learn the addition symbol (+) and use it in number sentences, along with
the equals sign they learned earlier. Now, students connect word sentences
and number sentences (e.g. students know that 4 + 2 = 6 is another way to show
“4 add 2 makes 6”).
8.1
Introducing the Addition
Symbol (+)
Color the mice. Then write a matching addition sentence.
a.
Color 3 mice brown.
b.
=
+
Color 5 mice brown.
Glossary
=
+
Colorwrite
2 mice
brown. number d.
Colorusing
4 micethe
brown.
In Lesson 1,c.students
addition
sentences
addition symbol.
• The commutative (or turnaround) property of addition says that it makes no difference
in which order two numbers are added (e.g. 3 + 5 = 8 and 5 + 3 = 8 are both true).
8.2
• To practice counting on, roll
two dice and ask your child to
name the bigger number and
the smaller number. Ask, “If
we want to know how many
in all, which number should
we start with?” Some children
still like to count all the dots
just to be sure. With time and
practice, they will become
confident in naming the
bigger number and counting
on the smaller number.
Clothes pins on a hanger
show the commutative
property of addition. Turning
the hanger around shows the
turnaround fact 3 + 2 = 5.
Using the Commutative
Property of Addition
5
Write two addition sentences to match the domino.
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a.
+
+
=
=
b.
+
+
=
=
+
=
+
=
c.
In Lesson 2, students
read and write turnaroundd.number facts to match domino pictures.
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+
+
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=
+
=
• Students use the turnaround idea to practice the addition strategy “think big, count
small”. It is more efficient to start with the bigger number and count on the smaller
number (e.g. for 2 + 5, think “5, 6, 7” rather than “2, 3, 4, 5, 6, 7”). Students learn that
they can change the order
=
+ of the =numbers before adding.
+
e.
2+3=5
57
ORIGO Stepping Stones K • 8.1
=
f.
+
=
Dominos are used to
practice the “think big, count
small” strategy.
9+ 1
1+9
6+ 1
1+ 6
4+ 2
2+ 4
2+ 8
8+ 2
1
Grade K, Module 8
8.3
Introducing the “Think Big,
Count Small” Idea
Ideas for Home
Complete the addition sentence. Write the greater number first.
a.
1
+
4
b.
5
=
+
2
=
In Lessonc.3, students practice starting with d.
the greater number and then counting
on the smaller number, regardless of order.
2
6
2
4
1
7
• Because our number system is based on tens, it is especially important for students
to learn to recognize all the various ways that a set of 10 objects can be broken into
two smaller sets (1 + 9, 2 + 8, 3 + 7, all the way to 9 + 1).
=
=
+
+
8.4
e.
Identifying Two Parts
that Total 10
3
2
f.
Draw more dots to make 10. Then complete the addition sentence.
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a.
+
=
+
=
ORIGO Stepping Stones K • 8.3
b.
10 10
+
=
=
+
59
d. to show the number 10 as the sum
In Lessonc.4, students investigate different ways
of two parts.
Geometry: 2D Shapes and 3D Objects
• Students investigate two-dimensional shapes and three-dimensional objects. They
match pictures of 3D objects
with
names
(sphere, cube,
= their formal geometric
+
+
=
cone, and cylinder).
10 10
e.
8.6a
• Have your child count out
10 pennies into a cup. Turn
the cup over to spill the
pennies and have your child
count the number of pennies
that landed heads up and the
number that landed tails up.
Keep playing to find different
combinations for 10.
• Discuss the difference
between 2D shapes and
3D objects. 2D shapes are as
flat as possible. Your child can
hold them between two hands
pressed flat together. But
when they hold a 3D object,
they cannot put their hands
completely flat together.
• When reading with your
child, ask them to look for
pictures of things they know
are in your home (e.g. a
backpack or pair of shoes).
Have your child compare
the 3D object to its 2D
representation in the book.
Ask questions such as “How
are these the same?” and
“How are they different?”
f.
Sorting 2D Shapes
and 3D Objects
Glossary
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Cut out the pictures.
Then sort and paste them where they belong on page 63.
+
=
10 10
=
+
ORIGO Stepping Stones K • 8.4
60
© ORIGO Education.
In Lesson 6, students compare and sort 3D objects and 2D shapes.
2
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