Lesson Plan
Two-Digit Dash!
Students will be able to accurately add two-digit numbers within 100 using various strategies.
Mastering two-digit addition is crucial for building a strong foundation in math and for everyday problem-solving, like calculating totals when shopping or keeping score in games.
Audience
2nd Grade Students
Time
15 minutes
Approach
Through an engaging card game, students will practice mental math and strategies for adding two-digit numbers.
Materials
Dice (2 per group), Playing Cards (without face cards, 2-9 per group), Two-Digit Dash! Game Instructions, Two-Digit Dash! Recording Sheet, and Two-Digit Dash! Answer Key
Prep
Gather Materials & Review
5 minutes
- Gather 2 dice and a deck of playing cards (remove face cards and 10s) for each small group.
- Print and cut out one Two-Digit Dash! Game Instructions per group.
- Print one Two-Digit Dash! Recording Sheet per student.
- Print one Two-Digit Dash! Answer Key per group for self-checking.
- Review all generated materials as needed.
Step 1
Introduction (2 minutes)
2 minutes
- Briefly explain the game 'Two-Digit Dash!' and its objective: to practice adding two-digit numbers.
- Distribute the game materials to each small group.
Step 2
Explain Game Rules (5 minutes)
5 minutes
- Refer to the Two-Digit Dash! Game Instructions.
- Demonstrate how to play by rolling dice, drawing cards, forming two-digit numbers, and adding them.
- Emphasize using the Two-Digit Dash! Recording Sheet to show their work and the Two-Digit Dash! Answer Key for self-correction.
Step 3
Play Game (7 minutes)
7 minutes
- Have students play 'Two-Digit Dash!' in their small groups.
- Circulate among groups to provide support, answer questions, and observe strategies.
- Encourage students to help each other and explain their thinking.
Step 4
Wrap-up (1 minute)
1 minute
- Announce the end of the game.
- Collect materials and briefly check for understanding with a quick question about a strategy they used.
use Lenny to create lessons.
No credit card needed
Game
Two-Digit Dash! Game Instructions
Players: 2-4
Materials: 2 Dice, Deck of Playing Cards (Aces=1, remove face cards and 10s), Two-Digit Dash! Recording Sheet, Two-Digit Dash! Answer Key
Objective: Be the player with the most points after 5 rounds by correctly adding two-digit numbers!
How to Play:
- Set Up: Each player gets a Two-Digit Dash! Recording Sheet. Place the deck of cards face down in the center. Everyone should have a pencil.
- Player 1 Starts: The first player rolls both dice.
- They use the numbers rolled to create their first two-digit number. For example, if they roll a 3 and a 5, they can make 35 or 53. They choose the number they want.
- Draw Cards: The same player then draws two cards from the deck.
- These two cards are used to create their second two-digit number. For example, if they draw a 4 and a 7, they can make 47 or 74. They choose the number they want.
- Add 'Em Up! The player adds their two chosen two-digit numbers together (e.g., 53 + 74).
- They write the addition problem and their answer on their Two-Digit Dash! Recording Sheet for the current round.
- Check Your Work: The player then checks their answer using the Two-Digit Dash! Answer Key.
- If their answer is correct, they get 1 point for that round. If it's incorrect, they get 0 points.
- Next Player: Play passes to the next player, who follows steps 2-5.
- Winning: After 5 rounds, players total their points. The player with the most points wins!
Worksheet
Two-Digit Dash! Recording Sheet
Name: _____________________________
Instructions:
For each round, write down the two two-digit numbers you create and show your addition work. Then, write your answer and check if it's correct!
Round 1
Numbers: ______ + ______
Work:
Answer: ______ Correct? (Circle one): Yes / No
Round 2
Numbers: ______ + ______
Work:
Answer: ______ Correct? (Circle one): Yes / No
Round 3
Numbers: ______ + ______
Work:
Answer: ______ Correct? (Circle one): Yes / No
Round 4
Numbers: ______ + ______
Work:
Answer: ______ Correct? (Circle one): Yes / No
Round 5
Numbers: ______ + ______
Work:
Answer: ______ Correct? (Circle one): Yes / No
Total Points:
My Score: _________ (Count how many
Answer Key
Two-Digit Dash! Answer Key
How to Check Your Answers:
Since the numbers you create with dice and cards will be different each time, this answer key will help you understand how to check your addition.
Method 1: Use the Standard Algorithm
- Line Up: Write your two-digit numbers one below the other, making sure the ones digits are lined up and the tens digits are lined up.
35 + 42 ----- - Add the Ones: Add the digits in the ones place first.
- Example: 5 + 2 = 7
35 + 42 ----- 7 - Add the Tens: Add the digits in the tens place.
- Example: 3 + 4 = 7
35 + 42 ----- 77 - Regroup if Needed: If the sum of the ones digits is 10 or more, you need to regroup! Write the ones digit of the sum in the ones place and carry over the tens digit to the tens column.
- Example: 38 + 25
- Add ones: 8 + 5 = 13. Write down 3, carry over 1 to the tens place.
¹ 38 + 25 ----- 3- Add tens (including the regrouped digit): 1 + 3 + 2 = 6
¹ 38 + 25 ----- 63
Method 2: Use a Calculator (If Available for Self-Checking)
After you have solved the problem on your own, you can use a simple calculator to quickly check your final sum. Remember to always try to solve it yourself first!
Always double-check your work! It's great to find your own mistakes and learn from them!