Operation Unknown Script Master Investigation Guide
Day 2: TEKS 3.5D Unknowns
25 Minute Mission
Mission Objective
Students will determine unknown numbers in multiplication/division equations using fact families and strip diagrams, including symbols and multi-select formats.
Required Gear
Operation Unknown Worksheet
Dry erase markers/boards for modeling
Phase 1: Code Breaking 0:00 - 0:05
SAY:
"Agents, we have a code-breaking mission. In math, when a number is missing, it's an 'unknown.' It might be a box, a question mark, or even a blank space. To find it, we use the fact family relationship."
Write \( 3 \times \square = 21 \) and \( 21 \div 3 = \square \). Ask: "What number lives in this family?" (7). Point out that multiplication and division are partners.
Phase 2: Modeling the Evidence 0:05 - 0:15
GUIDE:
Look at Part 1 on the worksheet.
TEACHER TIP:
For multi-select questions, teach students to 'Try Each Key.' Check if EVERY equation works with the numbers in the story.
Phase 3: Final Mastery Check 0:15 - 0:25
DO:
Students complete Part 2. Circulate and check for the "Inverse Error" (students adding when they should divide).
Check: Are they checking all options in the multi-select question?
Check: Are they using fact families for the open response?
Operation Unknown Worksheet Operation Unknown
Intensive Mission Case #35D
Agent:
Date:
Part 1: Evidence Modeling
Inverse Thinking
Find the missing number:
\( 54 \div \square = 6 \)
Work Space
Visual Evidence
What is the missing number?
32
?
?
?
?
\( \square = \) ____
Part 2: STAAR Mastery Check
"A detective put 42 magnifying glasses into 7 boxes. There was an equal number of magnifying glasses in each box."
Select TWO equations that can find the number of magnifying glasses in each box.
\( 42 \div 7 = \square \)
\( 42 \times 7 = \square \)
\( 7 \times \square = 42 \)
\( 42 + 7 = \square \)
What number makes the equation true?
\( 8 \times \square = 64 \)
____
Which equation belongs in the same fact family as \( 3 \times 9 = 27 \)?
\( 27 \div 3 = 9 \)
\( 27 - 3 = 24 \)
\( 27 + 9 = 36 \)
\( 9 \times 9 = 81 \)
TOP SECRET
Operation Unknown Key Case Solved
Intensive Mission Answer Key
TEACHER ONLY
Part 1: Evidence Modeling
Problem A
\( 54 \div \mathbf{9} = 6 \)
Answer: 9
Problem B (Strip Diagram)
\( 32 \div 4 = \mathbf{8} \)
Value of n: 8
Part 2: STAAR Mastery Check
1. Multi-Select (Select Two) 2 Correct Answers
\( 42 \div 7 = \square \)
\( 7 \times \square = 42 \)
2. Open Response \( 8 \times \square = 64 \)
8
3. Fact Family Matching
\( 27 \div 3 = 9 \)
Misconception Alert
Students often select "42 x 7" for word problems like Question 1. Remind them that the total is 42, and multiplication with a total already known would lead to a much larger number, which doesn't fit the story.
Quick Case Exit Ticket Quick Case
Exit Ticket #35D
Agent:
An agent solved the equation below. What is the missing number?
\( 72 \div \square = 9 \)
81
63
8
7
What number makes the equation true?
\( \square \times 6 = 48 \)
____
Look at the strip diagram.
45
?
?
?
?
?
Which equation finds the missing number in each group?
\( 45 \div 5 = \square \)
\( 45 + 5 = \square \)
\( 45 \times 5 = \square \)
MISSION COMPLETE
Quick Case Key Quick Case Key
Exit Ticket #35D Answers
TEACHER ONLY
\( 72 \div \square = 9 \)
8
\( \square \times 6 = 48 \)
8
3. Strip Diagram
\( 45 \div 5 = \square \)
Scoring Note:
3/3 = Expert Detective | 2/3 = Field Agent | 1/3 = Trainee. Use for quick formative data.
Fair Share Teacher Script Fair Share Script
Day 3: Partitioning Sets (TEKS 3.4H)
25 Minute Intervention
Learning Target
Students will determine the number of objects in each group when a total set is shared equally into a known number of groups.
Evidence Bag
Fair Share Worksheet
12-24 small counters (beans, cubes, or pennies)
Paper plates or "group circles"
Phase 1: The Equal Share Problem 0:00 - 0:05
SAY:
"Agents, today's case is about fairness. Imagine we have 12 gold coins, and we need to share them equally between 3 detectives. If we give one to each person until they are gone, how many coins does each person get?"
DO:
Quickly model this with 12 counters and 3 circles. Deal them out 'one for you, one for you, one for you' until finished.
Phase 2: Partitioning Evidence 0:05 - 0:15
GUIDE:
Transition to the Fair Share Worksheet, Part 1.
"Look at the first question. We have 18 total badges and 6 agents. To solve this, we can draw 6 circles and put one dot in each until we hit 18. Let's try it together."
Teacher Prompt:
"Does the number of groups change? (No, it's 6). What are we finding? (The number in EACH group)."
Phase 3: Case Closed Practice 0:15 - 0:25
SAY:
"On your final test, they might show you pictures of groups and ask you which one shows equal shares. Remember: to be a 'Fair Share,' every single group must have the exact same amount."
Have students work independently on Part 2. Watch for students who try to 'count all' instead of using their division facts or partitioning models.
Fair Share Worksheet The Fair Share Caper
Mission File #3.4H
Agent:
Date:
Part 1: Shared Evidence
Investigation: A detective has 18 badges. She shares them equally into 6 evidence bags.
Draw dots to show the badges shared into the bags below:
There are badges in each bag.
Part 2: STAAR Practice
Marcus has 24 stickers. He puts an equal number of stickers onto 4 pages in a notebook. Which model shows the number of stickers Marcus puts on each page?
4
4
4
4
6
6
6
6
12
12
8
8
8
A group of 35 students is being split equally into 5 teams. How many students will be on each team?
Team 1
Team 2
Team 3
Team 4
Team 5
Show Work Area
Answer: students
A baker has 24 cookies. He puts them into 3 boxes. He puts the same number of cookies in each box. Which equation shows how many cookies are in each box?
\( 24 \div 3 = 8 \)
\( 24 - 3 = 21 \)
\( 24 + 3 = 27 \)
\( 3 \times 24 = 72 \)
Fair Share Key Caper Closed
Fair Share Answer Key (3.4H)
TEACHER ONLY
Part 1: Shared Evidence
18 badges / 6 bags
3 dots
3 dots
3 dots
3 dots
3 dots
3 dots
Correct Answer: 3 badges per bag
Part 2: STAAR Practice
1. Sticker Notebook Model Correct Answer
The model showing 4 groups with 6 in each.
Explanation: \( 24 \div 4 = 6 \). Only the second choice has 4 boxes containing 6.
2. Team Split Word Problem \( 35 \div 5 = \text{?} \)
7 students
3. Baker's Cookie Equation
\( 24 \div 3 = 8 \)
Intervention Tip
If students struggle with sharing, have them act it out with physical manipulatives. Ensure they understand that the "number of groups" is the divisor and the "number in each group" is the quotient.
Fair Share Exit Ticket The Final Share
Exit Ticket #3.4H
Agent:
An agent has 15 clues. He puts them into 3 equal groups. Which model shows how many clues are in each group?
5
5
5
3
3
3
5
5
5
5
15
A group of 32 detectives is split equally into 4 teams. How many detectives are on each team?
____
Record your answer in the box.
Which equation can be used to find the number of objects in each group when 18 objects are partitioned into 2 equal shares?
\( 18 \div 2 = 9 \)
\( 18 \times 2 = 36 \)
\( 18 - 2 = 16 \)
\( 18 + 2 = 20 \)
CASE CLOSED
Fair Share Exit Key Fair Share Exit Key
Exit Ticket #3.4H Answers
TEACHER ONLY
1. Model Selection 15 clues / 3 groups
Model with 3 boxes of 5
2. Detective Teams \( 32 \div 4 = \text{?} \)
8 detectives
3. Partitioning Equation
\( 18 \div 2 = 9 \)
Formative Feedback:
Use this to identify students who may need support distinguishing between "sharing equally" (division) and "adding to" or "multiplying" sets.
RDW Code Breaker Script RDW Script
Day 4: Multi-Step Addition & Subtraction (TEKS 3.4A)
25 Minute Intervention
Mission Target
Students will use the RDW (Read, Draw, Write) process to solve one-step and two-step addition and subtraction problems within 1,000.
Detective Tools
RDW Code Breaker Worksheet
Place value disks or blocks (optional support)
Phase 1: The RDW Protocol 0:00 - 0:05
SAY:
"Agents, sometimes a case has multiple steps. To solve it without getting lost, we use the RDW protocol.Read: Investigate (read) the clues and understand the situation.Draw: Map the evidence with a strip diagram or model.Write: Solve with an equation and a final answer."
Write 450 + 120 - 30 on the board. Ask: "If we just guess, we might fail. Let's see how RDW keeps us on track."
Phase 2: The Two-Step Investigation 0:05 - 0:15
GUIDE:
"Look at Part 1 on your worksheet. It says: 'A shop had 500 badges. They sold 125 in the morning and 80 in the afternoon. How many are left?'"
Walk students through the drawing phase. Show two ways:
One big subtraction: \( 500 - (125 + 80) \)
Step-by-step: \( 500 - 125 = 375 \), then \( 375 - 80 = 295 \).
Tactical Note:
Encourage students to use 'friendly numbers' or 'expanded form' if the standard algorithm is causing errors.
Phase 3: Independent Code Breaking 0:15 - 0:25
DO:
Students complete the STAAR practice section. Watch for the "One-Step Trap"—students who stop after the first operation in a two-step problem.
Debrief: "Why do we draw the evidence before we write the equation?"
RDW Code Breaker Worksheet RDW Code Breaker
Mission File #3.4A
Agent:
Date:
Part 1: The RDW Protocol
Case #101: The Badge Mystery
Read (Investigate & Understand)
An agent had 450 badges. He gave 175 badges to a partner and found 60 more badges in a drawer. How many badges does the agent have now?
Draw (Map the Evidence)
Write (Solve the Case)
Part 2: Case Closed Practice
A museum had 845 visitors on Saturday. There were 215 children and 360 men. The rest of the visitors were women. How many women visited the museum on Saturday?
575
270
630
485
RDW Scratchpad:
An agent found 350 clues on Monday and 215 clues on Tuesday. On Wednesday, the agent lost 140 of the clues. How many clues does the agent have left?
Final Answer
Record your answer in the box.
Last year, 612 people attended a basketball game. This year, 145 fewer people attended than last year. How many people attended the game this year?
757
467
477
533
CLASSIFIED
RDW Key Mission Debugged
RDW Answer Key (3.4A)
TEACHER ONLY
Part 1: The RDW Protocol
Case #101 Solutions
Step 1: \( 450 - 175 = 275 \)
Correct Answer: 335 badges
Note: Drawing should show a strip with 450 total, taking away 175, then adding a small box for 60.
Part 2: Case Closed Practice
1. Museum Visitor Two-Step Solution: 270
Work: \( 215 + 360 = 575 \). Then \( 845 - 575 = 270 \).
2. Two-Step Clue Problem \( 350 + 215 = 565 \), \( 565 - 140 = \text{?} \)
425 clues
3. Basketball Attendance
467
Work: \( 612 - 145 = 467 \). (Check for regrouping errors).
Common Errors
Regrouping: Watch for \( 2 - 5 = 3 \) errors in the ones place of Q3.Partial Completion: In Q1 and Q2, students may stop after the first step. Weekly Case File Assessment Weekly Case File
Cumulative Assessment: Days 1-4
Agent:
Date:
Complete all tasks independently. Use your RDW strategies for word problems.
Task 1: Missing Numbers
1. Which number makes this true?
\( 48 \div \square = 6 \)
42
8
7
54
2. Select TWO true equations for 7.
\( \square \times 4 = 28 \)
\( 35 \div \square = 5 \)
\( 7 \times 7 = 14 \)
\( 63 \div \square = 7 \)
Task 2: Fair Shares
3. Ms. Davis has 32 markers. She puts them into 8 boxes equally. How many in each box?
Answer:
4. 12 objects shared into 4 groups?
Task 3: Multiplication
5. Which fact does this represent?
\( 3 \times 7 = 21 \)
\( 3 + 7 = 10 \)
Task 4: Two-Step Case
6. 750 boxes total. Ship 215 Mon, ship 188 Tue. How many are left?
Draw
Solve
Ans
CASE CLOSED
Weekly Case File Key Mission Accomplished
Weekly Case File Key: Days 1-4
TEACHER ONLY
Task 1
1. \( 48 \div \square = 6 \) 8
2. Multi-Select
\( \square \times 4 = 28 \)
\( 35 \div \square = 5 \)
Task 2
3. 32 / 8 4 markers
4. Model
Model with 4 groups of 3
Task 3
5. Array Fact
\( 3 \times 7 = 21 \)
Task 4
6. Two-Step
\( 215 + 188 = 403 \)
\( 750 - 403 = 347 \)
Ans: 347 boxes
Detective Promotion Guide
6/6 Correct
Lead Detective
4-5 Correct
Field Agent
0-3 Correct
Trainee
