Penguin Math: Double-Digit Addition & Subtraction
Students take on the role of zookeepers at the Penguin Coast exhibit inside the Birdhouse at Riverbanks Zoo & Garden in Columbia, SC. Using place value strategies and base-ten blocks, students solve real-world addition and subtraction problems as they track King, Rockhopper, and Gentoo penguins during feeding times and exhibit care.
Essential Question
How do we determine whether to use addition or subtraction to keep track of animals in a zoo exhibit?
Grade(s):
- 2
Subject(s):
Recommended Technology:
- Smart Board w/ audio to view the Zoo Minutes | Penguins video
Other Instructional Materials or Notes:
Base-ten blocks (tens rods and ones cubes)
Photos or video clips of the Penguin Coast exhibit at Riverbanks Zoo
Student Worksheet: "Riverbanks Zoo: Penguin Coast Patrol"
Lesson Progression
1. Hook & Introduction (10 Minutes)
- SCETV Media Anchor: Stream the short Zoo Minutes: Penguins segment from KnowItAll.org. Have students pay close attention to how the penguins move between the land/rocky areas and the deep swimming pool.
Story Scenario: Tell students: "Today, we are guest zookeepers at Riverbanks Zoo! Our job is to help the care team keep track of the King and Rockhopper penguins living at Penguin Coast."
Operation Anchor:
Joining / Coming Together / Total: We ADD (+).
Leaving / Diving into Water / Remaining: We SUBTRACT (-).
2. Direct Instruction: Model Problems (12 Minutes)
Demonstrate how to analyze word problems using base-ten strategies:
Model 1 (Addition with Regrouping):
"The zookeepers counted
38 Rockhopper penguins resting on the artificial ice rocks. A team brought out 25 King penguins to join them. How many penguins are on the rocks altogether?" Operation: Joining -> Addition (38 + 25).
Base-Ten Strategy: 3 tens + 2 tens = 5 tens (50). 8 ones + 5 ones = 13 ones. Regroup 10 ones into 1 ten -> 63 penguins.
Model 2 (Subtraction with Regrouping):
"There were
52 penguins gathered near the big glass viewing window at Penguin Coast. During the 11:30am feeding talk, 27 penguins dove into the deep water to catch fish. How many penguins stayed on the rocky shore?" Operation: Leaving -> Subtraction (52 - 27).
Base-Ten Strategy: Trade 1 ten for 10 ones (4 tens, 12 ones). Subtract 7 ones (5) and 2 tens (2) -> 25 penguins.
3. Transition to Independent & Partner Practice (5 Minutes)
Distribute the "Riverbanks Zoo: Penguin Coast Patrol" worksheet and base-ten blocks to students.
Explicit Directions to Students:
"You are now officially on duty as guest zookeepers! Hand out your base-ten blocks at your table."
"Read each problem carefully. Before you write any numbers, circle the action word that tells you what the penguins are doing."
"Decide if the group is joining together (ADD) or diving away/leaving (SUBTRACT), and write the + or - sign in your work space."
"Build the problem using your base-ten blocks on your desk. Remember: if you have more than 10 ones when adding, make an Ice Trade (regroup 10 ones for 1 ten rod). If you don't have enough ones when subtracting, break down 1 ten rod into 10 ones."
"Complete Problems 1 through 4 independently or with your elbow partner. When you finish, try the Bonus Challenge at the bottom!"
4. Guided Work Time & Closure (18 Minutes)
Circulation: Teacher moves around the room monitoring base-ten block setups, offering targeted support on regrouping trades, and checking operational choices.
Wrap-Up: Gather back as a class to review answers together and share strategies used for the Bonus Challenge.
Teacher Notes
Differentiation: Provide place value mats labeled Tens and Ones alongside physical base-ten blocks. Use color-coded highlighters on key action words ("joined," "dove into water," "altogether," "left") to guide operational choices.
Extension: Have students design their own two-step word problem featuring the 3 penguin species at Riverbanks Zoo.
Assessments
Use the performance task linked in the resources tab to assess student learning outcomes.
