# “Marsupial Math” is a lesson on Subtraction Sentences

Subject:

Math

K, 1

Title – Marsupial Math
By – Dana L. Craig
Primary Subject – Math
Secondary Subjects –
“Marsupial Math”

Concepts to be taught:

• Subtraction
• Writing subtraction sentences

Behavioral Objectives:

• The student will be able to show how to solve subtraction problems using manipulative materials and deductive reasoning.
• The student will be able to construct subtraction sentences using information from the activity.

Materials/ Media Needed:

• Construction Paper Made “Kathy Kangaroo”
• Construction Paper Made “Joeys” attached to clothespins
• Worksheets for activity

Note from LessonPlansPage.com: This lesson plan involves a worksheet that is not included. You may be able to create your own version of the worksheet or contact the author at the email address at the bottom of this lesson plan to request a copy.

Teaching/ Learning Procedure:

2. “What special feature do marsupials have?” (Pouches)
3. “Can you think of the name of a marsupial?” (Kangaroo)

B. Instructional Strategy: Say to the children:

“This is Kathy Kangaroo and her three joeys. One day two of her friends asked her to baby-sit their joeys too. One friend had three gray joeys and her other friend had four dark brown joeys. Let’s count how many joeys that Kathy has now. (Count the joeys to ten as they hop in the pouch.)

Now instead of only three joeys to watch for the day- poor Kathy has to keep up with ten! Now you can imagine how hard it must be for Kathy Kangaroo to watch those mischievous joeys all by herself! Kathy asked the joeys to crawl inside her pouch to take a nap, but the joeys would not behave. Kathy tried and tried to calm those joeys down but every time she turned around those naughty joeys were hopping out of her pouch! Kathy made a naughty list so that she would know which of the joeys would not get a treat for snack. Let’s look at the notes that Kathy made on her naughty list.” (Marsupial Math worksheet)

“Can you look at the list and the joeys that are in her pouch and help her figure out how many joeys hopped out of the pouch? Can you help Kathy figure out how many joeys deserve a treat for remaining in the pouch? Do you remember how we wrote addition sentences?” (If no, quick review. If yes, go on.)

“Subtraction sentences are written a lot like addition sentences but when we write a subtraction sentence, we write down the number that we start with first, and then we listen for how many are taken away from the whole amount. The answer is how many you have left. Listen carefully to what I say and write an appropriate subtraction sentence to show how many joeys were in Kathy’s pouch each time and how many hopped out.” (Read questions from worksheet as you pull the joeys from the pouch.)

Have the children share their answers orally after writing their sentences. Walk around and observe what the children are writing as I pull joeys from the pouch.

If child has the wrong answer ask why they answered that way and ask them to watch how many joeys are in the pouch and how many hop out. (Demonstrate for them again.)

• “‘Do you think we found all the joeys? Let’s count them all to be sure that they are all back inside Kathy’s pouch.” (Count all the joeys to ten.)
• “How many joeys deserve a treat for staying in the pouch?” (2)
• “What happens when we subtract?” (We take things away.)
• “Kathy Kangaroo would like to thank you for all your help in finding the missing joeys and I am sure that her friends would thank you too!”

Evaluation:

After the completion of the lesson, I will ask the children the following questions and have them to perform the following activities:

• Repeat: “What does it mean to subtract?” (You take things away from a whole)
• “Let’s think of times when you have had to subtract things in your life.” (Taking handwriting papers from the stack, drinks from a six-pack, etc.)
• “In the kangaroo lesson, how many joeys did we have to begin with?” (10)
• “Can you write two different subtraction problems by subtracting a number from the whole number ten and give me the answer?” (10-2=8, 10-5=5, 10-6=4, etc.)

Email me at dlcraig@gulftel.com for a copy of the worksheet.

E-Mail Dana L. Craig !