Lesson Plan
Sum & Minus Sprint Plan
Students will fluently add and subtract within 20 by engaging in rapid-fire warm-ups, teacher-led modeling, guided partner work, and independent practice in a focused 15-minute sprint.
Quick, targeted practice builds arithmetic fluency and confidence, ensuring students master foundational addition and subtraction skills needed for everyday math and future concepts.
Audience
2nd Grade
Time
15 minutes
Approach
Interactive modeling and timed practice rounds
Materials
Dry-Erase Whiteboard, Marker Set, Plastic Counting Counters, Sum & Minus Sprint Worksheet, Addition & Subtraction Flashcards, and Classroom Timer
Prep
Material Preparation
5 minutes
- Print and copy enough Sum & Minus Sprint Worksheet for each student
- Gather a set of Addition & Subtraction Flashcards and shuffle
- Arrange dry-erase whiteboard and markers at the front of the class
- Place counting counters within reach of students
- Set up the Classroom Timer for warm-up and practice intervals
Step 1
Warm-Up Drill
2 minutes
- Use the timer to do a 90-second rapid flashcard round with the whole class
- Show each Addition & Subtraction Flashcard and have students call out answers aloud
- Aim for quick pace to build speed and focus
Step 2
Direct Instruction
3 minutes
- Model two addition and two subtraction problems within 20 on the whiteboard
- Use counting counters to demonstrate strategies (e.g., making ten, counting on)
- Verbally walk through each step, highlighting number bonds and mental math tips
Step 3
Guided Practice
4 minutes
- Project or write three new problems on the board
- Call on volunteer pairs to solve each problem with counters at the board
- Prompt peers to explain the strategy used and correct any misconceptions
Step 4
Independent Practice
4 minutes
- Distribute the Sum & Minus Sprint Worksheet
- Students complete ten mixed addition/subtraction problems within 4 minutes
- Monitor progress and offer quick support for students who struggle
Step 5
Cool-Down and Review
2 minutes
- Reconvene as a class and review two student answers from the worksheet
- Highlight efficient strategies observed
- End with a 30-second flashcard lightning round for fun reinforcement
use Lenny to create lessons.
No credit card needed
Slide Deck
Sum & Minus Sprint
• Objective: Fluently add & subtract within 20
• Time: 15 minutes
• Today’s Flow: Warm-Up → Modeling → Guided → Independent → Cool-Down
Welcome students. Introduce today’s 15-minute sprint on adding and subtracting within 20. Emphasize speed, focus, and fun!
Agenda
- 90-second Flashcard Drill
- Teacher-Modeled Examples
- Partner Problem Solving
- 10-Question Worksheet
- Review & Lightning Round
Briefly run through the agenda so students know what to expect. Keep it snappy.
Warm-Up Drill
• Use the Classroom Timer for 90 seconds
• Show each Addition & Subtraction Flashcard
• Students call out answers loudly and quickly
Start the timer for 90 seconds. Show flashcards quickly and have students call out answers.
Teacher-Modeled Examples
- 8 + 5 = 13 (Use counters to make ten then add 3)
- 14 − 6 = 8 (Subtract to ten then the rest)
- 7 + 9 = 16 (Count on from 7)
- 12 − 4 = 8 (Use number bonds)
Model two addition and two subtraction problems. Use counters and think aloud.
Guided Practice
Solve with a partner at the board:
• 9 + 6 = ___
• 15 − 7 = ___
• 4 + 11 = ___
Peers share their thinking aloud.
Project the three problems. Invite pairs to the board with counters. Ask classmates to explain strategies.
Independent Practice
• Hand out the Sum & Minus Sprint Worksheet
• Complete 10 mixed problems in 4 minutes
• Work quietly; raise hand for help
Distribute the worksheet. Monitor progress and prompt quick mental strategies if needed.
Cool-Down & Review
• Review two student solutions from the worksheet
• Spotlight efficient strategies (making ten, counting on)
• 30-second flashcard lightning round for fun
Celebrate successes, highlight clever strategies, and end on a high-energy note with flashcards.
Worksheet
Sum & Minus Sprint Worksheet
Name: _______________________ Date: ____________
Instructions
Solve each addition or subtraction problem. Write your answer in the space provided and show your work if you wish.
- 7 + 8 = ________
- 14 − 5 = ________
- 9 + 6 = ________
- 12 − 4 = ________
- 8 + 11 = ________
- 17 − 9 = ________
- 5 + 13 = ________
- 19 − 7 = ________
- 6 + 6 = ________
- 16 − 8 = ________
Extension Challenge
- Maya has 12 apples. She gives 5 to her friend and then picks 7 more from the tree. How many apples does she have now? Show your work below.
- There are 20 balloons at a party. 8 balloons fly away, and then the guests add 9 more balloons. How many balloons are there altogether? Show your work below.
Great job sprinting through your sums and minuses! Keep practicing to build speed and confidence.
Answer Key
Sum & Minus Sprint Answer Key
Below are correct answers and step-by-step strategies for the 10 mixed problems, followed by fully worked solutions for the two extension challenges.
Basic Problems
- 7 + 8 = 15
Strategy: Break 8 into 3 + 5 so you can make ten first: 7 + 3 = 10, then 10 + 5 = 15. - 14 − 5 = 9
Strategy: Subtract 4 to reach ten (14 − 4 = 10), then subtract the remaining 1: 10 − 1 = 9. - 9 + 6 = 15
Strategy: Add 1 to 9 to make 10 (9 + 1 = 10), then add the remaining 5: 10 + 5 = 15. - 12 − 4 = 8
Strategy: Count back from 12: 12 → 11 (−1) → 10 (−1) → 9 (−1) → 8 (−1), four steps back. - 8 + 11 = 19
Strategy: Add 10 first (8 + 10 = 18), then add 1 more: 18 + 1 = 19. - 17 − 9 = 8
Strategy: Subtract 7 to make ten (17 − 7 = 10), then subtract 2 more: 10 − 2 = 8. - 5 + 13 = 18
Strategy: Add 5 + 5 = 10, then add the remaining 8: 10 + 8 = 18. - 19 − 7 = 12
Strategy: Subtract 9 to make ten (19 − 9 = 10), then add back 2 since you subtracted 2 too many: 10 + 2 = 12.
(Alternatively: 19 − 7: 19 → 12 by counting back seven steps.) - 6 + 6 = 12
Strategy: Recognize doubles: 6 + 6 = 12. - 16 − 8 = 8
Strategy: Half of 16 is 8, or subtract 6 to get to 10 (16 − 6 = 10), then subtract 2: 10 − 2 = 8.
Extension Challenge Problems
11. Maya’s Apples
Problem: Maya has 12 apples. She gives 5 to her friend and then picks 7 more.
Step-by-Step Solution:
- Subtract the 5 given away: 12 − 5 = 7 apples remain.
- Add the 7 she picks: 7 + 7 = 14 apples.
Answer: 14 apples
12. Party Balloons
Problem: There are 20 balloons. 8 fly away, then guests add 9 more.
Step-by-Step Solution:
- Subtract the 8 flown away: 20 − 8 = 12 balloons remain.
- Add the 9 new balloons: 12 + 9 = 21 balloons total.
Answer: 21 balloons
Use these worked solutions to guide grading and to show students efficient mental strategies: making ten, counting on or back, breaking numbers apart, and using known facts (doubles). Keep reinforcing these approaches to build fluency!
Warm Up
Flashcard Lightning
Instructions
Perform a 90-second rapid-fire flashcard round. Show each card one at a time and have students call out the answer aloud. Aim for quick pace and enthusiastic responses!
- 5 + 6 = ____
- 12 − 4 = ____
- 9 + 7 = ____
- 16 − 9 = ____
- 8 + 8 = ____
- 14 − 5 = ____
- 3 + 11 = ____
- 19 − 6 = ____
- 7 + 9 = ____
- 13 − 7 = ____
- 4 + 13 = ____
- 18 − 8 = ____
- 2 + 15 = ____
- 17 − 8 = ____
- 6 + 6 = ____
- 20 − 11 = ____
- 1 + 18 = ____
- 15 − 3 = ____
- 11 + 4 = ____
- 10 + 10 = ____
Cool Down
Lightning Recap
Exit Ticket
Take a minute to reflect on today’s sprint. Answer the questions below:
- Which strategy did you use most often to solve addition or subtraction problems (making ten, counting on/back, using doubles)? Why did it help you?
- What tip or trick will you remember to use next time to solve problems more quickly?
Discussion
Strategy Share Discussion
Purpose
Today we will talk about the different mental math strategies we used during our Sum & Minus Sprint. By sharing, we learn new tricks and help each other become faster math thinkers!
Discussion Guidelines
• Listen respectfully when others speak.
• Speak clearly and use examples.
• If you don’t understand, ask a follow-up question.
• Be kind and encouraging with your words.
Discussion Questions
- Which mental math strategy did you use most often today? (making ten, counting on/back, using doubles)
- Why did that strategy help you solve problems more quickly or easily?
- Show an example problem and explain how you used your strategy step by step.
- Which strategy would you like to try next time if you haven’t used it yet? How do you think it will help?
Possible Follow-Up Points
- Ask a friend: “Can you show me one more example of your strategy?”
- Compare: “When might counting on be faster than making ten? Why?”
- Challenge: “Can you solve 9 + 8 using two different strategies? Which was quicker?”
- Reflect: “How can using these strategies help us on other math problems?”
Feel free to use your Sum & Minus Sprint Worksheet or think back to the Addition & Subtraction Flashcards for examples!