Missing Numbers: Math Detective Script

Warm-Up: Number Hunt! (5 minutes)

"Good morning/afternoon, [Student Name]! Are you ready to put on your detective hat today? We're going on a 'Number Hunt' to find some missing numbers!"

"Let's start with a quick warm-up. I'm going to give you a simple math puzzle, and I want you to tell me what number is hiding. Listen carefully: 'I have 3 apples, and then I get some more. Now I have 7 apples. How many more apples did I get?'"

"That's right! You got 4 more apples. How did you figure that out? What was your strategy?"

"Excellent! Today, we're going to become super math detectives and learn a special trick to find any missing number in addition and subtraction problems."

Introduction: What's Missing? (5 minutes)

(Transition to Missing Numbers Slide Deck - Slide 1)

"Take a look at our first slide! Our mission today is to be a Math Detective and find those numbers that love to play hide-and-seek. Sometimes in math problems, a number is missing, and it's our job to discover what it is."

(Transition to Missing Numbers Slide Deck - Slide 2)

"To be great detectives, we need great tools! Today, our special tools are called Inverse Operations. Can you say 'inverse operations'?"

"Fantastic! Inverse operations just means that addition and subtraction are like best friends who can also undo each other. Think of it like this: if you put on your shoes (addition), you can take them off (subtraction). They are opposites! So, if we have an addition problem, we can use subtraction to solve it. And if we have a subtraction problem, we can use addition to solve it. It's like having a secret code to crack!"

Guided Practice: Solving Cases (10 minutes)

(Transition to Missing Numbers Slide Deck - Slide 3)

"Let's try our first case! Look at this problem: 5 + ? = 12. A number is missing! Our answer, 12, is the sum. What operation can we use to find the missing number, knowing that addition and subtraction are inverse operations?"

"You're on the right track! Since it's an addition problem, we can use subtraction to figure it out. We can say: 12 - 5 = ?. What do you get when you subtract 5 from 12?"

"That's it! 7! So, 5 + 7 = 12. Great job! The missing number was 7. See how subtraction helped us undo the addition?"

(Transition to Missing Numbers Slide Deck - Slide 4)

"Let's try another one. Our next mystery is: 15 - ? = 8. This time, we have a subtraction problem. What's the opposite operation we can use to find the missing number?"

"Exactly! We can use addition! When the missing number is in the middle of a subtraction problem, we can subtract the answer from the first number. So, it's 15 - 8 = ?. What does that equal?"

"You got it! 7! So, 15 - 7 = 8. Another case closed! You're becoming a pro at this, detective!"

Independent Practice: Your Turn, Detective! (7 minutes)

(Transition to Missing Numbers Slide Deck - Slide 5)

"You've got your detective tools down! Now it's time for you to practice your skills on your own. I have a Missing Numbers Worksheet for you with a few more cases to solve. Remember our secret code: addition mysteries can be solved with subtraction, and subtraction mysteries can be solved with addition. Take your time, and if you get stuck, just let me know!"

(Provide the student with the worksheet. Circulate and observe, offering gentle guidance if needed. If the student struggles with a particular type of problem, offer to work through one more example together.)

Wrap-Up: Crack the Code (3 minutes)

"You did an amazing job with your detective work today, [Student Name]! Let's quickly look at problem number [choose one or two problems the student worked on or struggled with]. How did you solve this one? What operation did you use?"

"That's fantastic! You clearly understand how inverse operations help us find missing numbers. You're well on your way to being a master math detective! Keep practicing, and you'll solve any number mystery that comes your way!"

Warm-Up: Number Hunt!

Can You Find the Missing Number?

Listen to these math puzzles and figure out which number is hiding!

1. I had 4 cookies, and my friend gave me some more. Now I have 10 cookies. How many cookies did my friend give me?
   
   
   
   
2. There were 12 birds in a tree. Some flew away. Now there are 5 birds left. How many birds flew away?
   
   
   
   
3. You have 7 crayons. You want to have 15 crayons in total. How many more crayons do you need?
   
   
   
   

Missing Numbers Worksheet: Math Detective Challenge!

Instructions: Be a math detective and find the missing number in each problem. Use inverse operations to solve the mystery!

Addition Cases:

1. 4 + ? = 11
   
   
   
   
   
   
   
2. ? + 6 = 14
   
   
   
   
   
   
   
3. 9 + ? = 17
   
   
   
   
   
   
   
4. ? + 8 = 16
   
   
   
   
   
   
   
5. 7 + ? = 13
   
   
   
   
   
   
   

Subtraction Cases:

6. 10 - ? = 6
   
   
   
   
   
   
   
7. ? - 5 = 9
   
   
   
   
   
   
   
8. 18 - ? = 9
   
   
   
   
   
   
   
9. ? - 7 = 7
   
   
   
   
   
   
   
10. 14 - ? = 6
    
    
    
    
    
    
    

Missing Numbers Answer Key

Instructions: Review the solutions below to check your detective work!

Addition Cases:

1. 4 + ? = 11
   • Thought Process: This is an addition problem. To find the missing number, use the inverse operation, which is subtraction. Subtract the known addend (4) from the sum (11).
   • Calculation: 11 - 4 = 7
   • Answer: 7
     
     
     
     
2. ? + 6 = 14
   • Thought Process: This is an addition problem. To find the missing number, use subtraction. Subtract the known addend (6) from the sum (14).
   • Calculation: 14 - 6 = 8
   • Answer: 8
     
     
     
     
3. 9 + ? = 17
   • Thought Process: This is an addition problem. Use subtraction to find the missing number. Subtract the known addend (9) from the sum (17).
   • Calculation: 17 - 9 = 8
   • Answer: 8
     
     
     
     
4. ? + 8 = 16
   • Thought Process: This is an addition problem. Use subtraction to find the missing number. Subtract the known addend (8) from the sum (16).
   • Calculation: 16 - 8 = 8
   • Answer: 8
     
     
     
     
5. 7 + ? = 13
   • Thought Process: This is an addition problem. Use subtraction to find the missing number. Subtract the known addend (7) from the sum (13).
   • Calculation: 13 - 7 = 6
   • Answer: 6
     
     
     
     

Subtraction Cases:

6. 10 - ? = 6
   • Thought Process: This is a subtraction problem where the number being subtracted is missing. To find it, you can subtract the difference (6) from the starting number (10).
   • Calculation: 10 - 6 = 4
   • Answer: 4
     
     
     
     
7. ? - 5 = 9
   • Thought Process: This is a subtraction problem where the starting number (minuend) is missing. To find it, use the inverse operation, addition. Add the number being subtracted (5) and the difference (9).
   • Calculation: 9 + 5 = 14
   • Answer: 14
     
     
     
     
8. 18 - ? = 9
   • Thought Process: This is a subtraction problem with the number being subtracted missing. Subtract the difference (9) from the starting number (18).
   • Calculation: 18 - 9 = 9
   • Answer: 9
     
     
     
     
9. ? - 7 = 7
   • Thought Process: This is a subtraction problem where the starting number is missing. Use addition. Add the number being subtracted (7) and the difference (7).
   • Calculation: 7 + 7 = 14
   • Answer: 14
     
     
     
     
10. 14 - ? = 6
    • Thought Process: This is a subtraction problem with the number being subtracted missing. Subtract the difference (6) from the starting number (14).
    • Calculation: 14 - 6 = 8
    • Answer: 8