For a brief overview of this lesson plan, please watch the following video.
Odd Man Out Lesson Plan Video
Snap
cubes are preferred for this activity. If none are available, provide 1" squares cut from cardstock.
Instead of having students build "two towers" with snap cubes, have students build "two towers" with the squares—two columns of
squares next to each other on a rigid piece of paper. Make sure each student also has a copy of each activity sheet.
Odd Man Out Activity Sheet
Odd Man Out Answer Key
Tower Power Activity Sheet
Tower Power Answer Key
Begin the lesson by introducing the term "odd man out"
by presenting a fictional scenario in which the students’ physical education
teacher will be providing dance lessons. For the lessons, each student will
need a partner. Have students form 2 equal lines facing each other, with
students directly across from each other. Tell the students that the person
they are facing is their "partner." If there is one student left
over, he/she is the "odd man out" or "odd person out"
because he/she doesn't have a partner. If all the students have partners, tell
the students you will be joining in. This makes you the "odd man out."
Have students return to their seats. Ask students what they think "odd man
out" means. Ask: "If there were 2 more students in the class, would
there still be an 'odd man out'?" [Yes.]
After students return to their seats, tell them they will be
looking at odd and even numbers today. Introduce "two towers" by
showing students how to snap sets of two cubes together and snapping the pairs
of cubes together to form a tower that is two cubes wide and some number of cubes tall. (If snap cubes aren't available, demonstrate
with paper squares. You may choose to use a document camera to demonstrate the
building of “towers”. Otherwise, you may do it on a desk or table where
students can gather around.) Reinforce the concept of pairs as you distribute
the snap cubes to students.
Tell students that they will be building towers based on a
number. Each cube will be paired up with a "partner." Have students
count off from 1 through 9, returning to 1 after the 9^{th} student.
Have each student create a "two tower" for the number he/she counted
off.
Give students time to build their towers. Once everyone has
finished, ask two students with even towers to bring them to the front of the
classroom (or the center of the classroom, especially if paper squares are
used).
Ask, "What do these towers have in common?" [Each
cube has a partner; there is no odd man out.] Ask, "If we put these two
towers together, do you think we'll get an odd number or an even number?"
[We'll get an even number because every cube will have a partner.]
Demonstrate putting the towers together to make a new "two
tower" to represent the sum. Record the information on the board by
creating a chart, shown below, or use the document camera to display the Tower
Power Activity Sheet.
(Example)
Addends | (even/odd)? + (even/odd)? | Is the sum
odd or even? |
2 + 4 | Even + Even | 2 + 4 = 6; Even |
Reinforce the meaning of odd and even numbers as you fill in
the chart.
Have two more students with even numbers combine their
towers in front of the class. Record the results in the chart. Ask, "Why
has the sum been even both times we've added even numbers?" [When even
numbers are added, they can always be divided into groups of 2. There is no odd man out in either tower we are adding.]
Now have two students who have "two towers" with
an odd man out show their towers. Ask, "What do these
towers have in common?" [Both have an odd man out. They both have a cube without a partner.]
Have the two students put their towers together and extend the
table with their results:
(Example)
Addends | (even/odd)? + (even/odd)? | Is the sum odd or
even? |
3 + 5 | Odd + Odd | 3 + 5 = 8; Even |
Repeat the process with two more students with "odd man
out" towers and record the results in the table. Ask, "Why has the
sum been even both times we've added odd numbers?" [When odd numbers are
added, the two "odd men out" become paired. There is no odd man out in the new tower.]
Next, have one student with an even numbered tower and one
student with an odd numbered tower show their towers. Ask, "If
we put these two towers together, do you think we'll get an odd number or an
even number?" [We'll get an odd number because the odd man out still won't
have a partner.]
Distribute the Tower Power Activity Sheet and have students put
together their own towers. Make sure students show the sum and record the
information in the chart:
(Example)
Addends | (even/odd)? + (even/odd)? | Is the sum odd or
even? |
4 + 5 | Even + Odd | 4 + 5 = 9; Odd |
Once students have about half of their charts filled out, have
students that combined an even number and an odd number tower to raise their
hands. Ask each student to state their addends and whether the sum was odd or
even. You may wish to write these on the board to have students comprehend that
an even + odd = odd. Have students also record the results in the activity
sheet. Ask, "Why has the sum been odd when we've added an even and an odd
number?" [The even number can be arranged in into groups of 2 with no cube left over, but when you
add the odd number to it, there's one cube left over.]
Ask students what they learned about adding even and odd
numbers. [Adding 2 evens gives an even sum; adding 2 odds gives an even sum;
adding one even and one odd gives an odd sum.] Students should first record
this on their Tower Power Activity Sheet, and then, share their findings with
the class.
Distribute the Odd Man Out Activity Sheet and have students
complete it. After students complete the
activity sheets, discuss the results as a class. Look for additional patterns,
or "sub-patterns." For example, the order of the numbers does not
matter when adding an even number and an odd number. Addition is commutative. So two conjectures could be
made:
- Odd plus even is always odd.
- Even plus odd is always odd.
Have students share any additional patterns they find.
Ideas for Differentiation
- Students who need a challenge can be asked to determine
whether or not the following sums will be odd or even:
- Even + Even + Even [= Even.]
- Even + Even + Odd [= Odd.]
- Even + Odd + Odd [= Even.]
- Odd + Odd + Odd [= Odd.]
- Encourage students to explain their thinking.
- For struggling students, the activity sheet can be modified
so that all or some of the numbers are single-digit.