LESSON PLAN 6: Add it Up!
IN BRIEF
The story Add it Up! offers the following insights:
The shepherd boy who cried wolf meets wolf and discovers neat
ways of adding numbers. For example:
29 + 35
= 30 + 35 - 1
= 65 - 1
= 64
But as Mama Wolf knits a new wool sweater, she giggles and says:
"Beware of wolves in sheeps’ clothing!"
From www.BrainyDay.ca
o in English
o in French
o in Spanish
As an eBook from iTunes,
Amazon & Kobo
CLASSROOM-TESTED
Add it Up! is classroom-tested in grades 2-4.
MATERIALS
 The story Add it Up! (see www.BrainyDay.ca)
 Activity Sheet 1 (attached)
Smart Math – Lesson Plan #6
www.BrainyDay.ca
page 1
LESSON DEVELOPMENT, Grades 2-6
Learning goals
Number Sense and Numeration
o Add 2-digit numbers
o Explore alternative addition strategies
o Use expanded notation
Communication
o Use words, numbers, symbols, diagrams, and storytelling to communicate learning
Reading of Add it Up!
Introduction
Before reading the story, ask students to share how they would add the numbers 29 and 35 in their
heads. Record and discuss various strategies. Repeat for numbers 18 and 46.
Reading
Read the story Add it Up! and pause at the end of page 10. Have students make connections between
the story problem and their activities. How does Wolf's strategy compare to the strategies they shared?
Is Wolf's strategy useful for all pairs of 2-digit numbers? Scaffold student thinking by asking them to
consider 25 + 35. Would Wolf's strategy be useful for this addition problem? Ask students to give other
examples where Wolf's strategy would be useful or not useful.
Finish reading the story and ask students to share what they learned from the story.
Student activity
Expanded notation and the method of "partition"
Model for students how to add 29 and 35 using expanded notation.
+
29
35
64
=
=
=
20
30
50
+
+
+
9
5
14
How else could the numbers 29 and 35 be "partitioned"? (Note that we are using the term "partitioning"
to mean rewriting a number as a sum. "Expanded notation" typically refers to partitioning a number
using place value, such as 125 = 100 + 20 + 5.] Model the solution below.
+
29
35
64
=
=
=
25
35
60
+
4
+
4
Have students use partitioning to find the sum of 46 and 18 in two different ways.
+
46
18
=
=
=
.
Share and discuss solutions. Have students complete Activity Sheet 1 (attached).
Smart Math – Lesson Plan #6
www.BrainyDay.ca
page 2
Extending
Model Wolf's method using partitioning and subtraction.
+
29
35
64
=
=
=
30
35
65
-
1
-
1
Have students use partitioning with subtraction to find the sum of 46 and 18.
+
46
18
=
=
=
.
Share and discuss solutions. Have students use partitioning with subtraction to find a third way of
adding the pairs of numbers in Activity Sheet 1 (attached).
Communicating
Students summarize their learning following teacher prompts such as: “What did you learn? What
surprised you? How did you feel?” Students use chart paper and colourful markers, and they
communicate their ideas using words, symbols, diagrams and pictures. They share their learning with
their peers, in a whole-class setting.
Sharing at home option. Students take their learning summaries home and share with parents.
Parent feedback option. Ask parents to send the following feedback:
o What did your child share with you?
o What did you learn from this activity?
Smart Math – Lesson Plan #6
www.BrainyDay.ca
page 3
ACTIVITY SHEET 1: Partitioning
Use partitioning to find the sum of the pairs of numbers in two different ways.
1. 49 + 14
+
49
14
=
=
=
.
+
49
14
=
=
=
.
35
25
=
=
=
.
+
35
25
=
=
=
.
28
24
=
=
=
.
+
28
24
=
=
=
.
37
13
=
=
=
.
+
37
13
=
=
=
.
44
17
=
=
=
.
+
44
17
=
=
=
.
57
28
=
=
=
+
57
28
=
=
=
.
2. 35 + 25
+
3. 28 + 24
+
4. 37 + 13
+
5. 44 + 17
+
6. 57 + 28
+
Smart Math – Lesson Plan #6
.
www.BrainyDay.ca
page 4