Reversal Rangers Teacher Guide Math Detectives • Lesson 1
Reversal Rangers
Instructional Guide • Focus: Number Writing & Fact Power
30 Minutes
Group Size: 5
Core Objectives
Write numbers 1-120 with zero reversals (focus: 12/21, 5, 9, 7).
Fluently solve addition math facts within 20.
Identify and self-correct backward-written numerals.
Required Materials
Lesson 1 Slides & Student Workbook
Dry-erase markers and small lap whiteboards
Numeral "Spy Glasses" (cardboard templates)
Lesson Breakdown & Pacing
5 Min Warm-Up
10 Min Direct Instruction
10 Min Guided Work
5 Min Exit Ticket
1. Fact Mission: Addition Power-Up
00:00 - 05:00
Students solve rapid-fire math facts on their whiteboards using the slides. Focus on strategy recall (e.g., "near doubles", "make ten").
Teacher Script: "Welcome, Math Detectives! Today we start our training. Before we can solve word problems, we need to charge our math engines. Look at slide 2. What is 8 + 7? Use 'double 7 plus 1' or 'make 10' to solve. Write it on your whiteboards in 5 seconds! Show me in 3... 2... 1... Reveal!"
2. Mini-Lesson: Clashing Numbers & Reversal Patrol
05:00 - 15:00
Model the exact stroke patterns for commonly reversed numerals (5, 9, 12 vs 21). Introduce the "Face-Forward Rules": e.g., 5 starts at the top, goes down, loops around, then gets a hat. Model on slide 3 and 4.
Teacher Script: "Now, detectives, a big case has landed. Numbers are swapping faces! Look at 12 and 21. The 'tens' place is powerful—12 means ten and two, while 21 means twenty and one! Let's trace our '5' and '9' together in the air. 5 goes: down, fat belly, then the hat! 9 is: make a circle first, then pull down a straight stick. No loops at the bottom!"
3. Guided Case: Error Patrol on the Grid
15:00 - 25:00
Have students open their workbook to Page 1. Model pointing out the "rever-suspects" on slide 5. Direct students to find and circle reversed numbers on their worksheets, then write them correctly inside the provided magnifying glass templates.
Teacher Script: "Grab your 'spy glasses' (magnifying glasses)! In your student logs, look at the number grid. Some numbers are sneaky—they are facing backwards or in the wrong place! Circle them with a red pencil. When you find one, write it correctly in the blank spy glass below."
Differentiation & Intervention Toolkit
Scaffolding (For Struggling Writers) Use a high-contrast yellow highlighter to write the dotted target number first. Have the student trace over the highlight with heavy tactile pencil pressure to lock in muscle memory.
Extension (For Advanced Students) Challenge students to fill out the 100-120 number sequence backward (120, 119, 118...) to strengthen place value comprehension and mental number line navigation.
Reversal Rangers Slides MATH DETECTIVES UNIT Session 1
REVERSAL RANGERS
Let's train our eyes to spot backward numbers and supercharge our math facts!
Get your whiteboards and dry-erase markers ready! Ready for Training • Slide 1/5
MISSION: FACT POWER-UP Warm-Up: 5 Mins
Clue #1: Near Doubles
8 + 7 = ___
Think: What is 7 + 7? Plus 1 more!
Clue #2: Make Ten
9 + 5 = ___
Think: 9 + 1 = 10, then add 4 more!
Clue #3: Near Doubles
6 + 8 = ___
Think: What is 6 + 6? Plus 2 more!
Clue #4: Make Ten
7 + 9 = ___
Think: 9 + 3 = 12, then add 4 more!
Write your answers on your whiteboard. Do not shout them out! Slide 2/5
REVERSAL PATROL: THE SUSPECTS Mini-Lesson
SUSPECT A Place Value Confusion
12
1 Ten, 2 Ones
vs
21
2 Tens, 1 One
The tens place has the power! Don't let them sneak-swap positions!
SUSPECT B Backward Numerals
5
Faces Right
vs
5
Faces Left (No!)
Remember: 5 faces the right! Keep its big belly forward!
Trace your fingers on your table to feel the difference! Slide 3/5
FACE-FORWARD RULES Stroke Patterns
5 The Number 5 Rule
Start at the top right.
Go down.
Give it a big belly loop facing right!
Lift up and draw its flat hat on top!
"Down, around, and put a lid on it!"
9 The Number 9 Rule
Start with a circle on top.
Connect back at the starting spot.
Draw a straight stick down.
No curling at the bottom!
"Make a circle, then a straight stick. Done!"
Let's air write these together! Reach high and trace! Slide 4/5
CASE FILE: SPOT THE IMPOSTORS! Case Challenge
Can your expert eyes spot the 3 reversed numbers hidden in this group?
15
5
#1
21
#2
92
105
54
112
9
#3
119
35
Point to the screen when you find one and tell us why it is backwards! Slide 5/5
Reversal Rangers Workbook Math Detectives • Student Case File
Reversal Rangers Training
Case Log: 001
Detective Name:
__________________________________________
Date:
________________________
Section 1: Fact Power-Up Warm-Up
CLUE #1 8 + 7 = ___
CLUE #2 9 + 5 = ___
CLUE #3 6 + 8 = ___
CLUE #4 7 + 9 = ___
Section 2: Reversal Patrol Training Lanes
5
Down, belly, hat!
5
5
9
Circle, straight down!
9
9
12 / 21
Watch the place!
12
21
Section 3: The 100-120 Grid Patrol
Write the missing numbers up to 120. Make sure they are facing the right way!
101
103
105
107
109
112
114
116
118
120
Mission 1 Ready for Review Math Detectives Intervention Program • Grade 2
Clue Catchers Teacher Guide Math Detectives • Lesson 2
Clue Catchers
Instructional Guide • Focus: Addition Word Problems to 200 & Sorting Info
30 Minutes
Group Size: 5
Core Objectives
Solve 1-step addition word problems up to 200.
Filter out extra information ("red herrings") using an organizer.
Use color-coded green keywords to identify addition operations.
Required Materials
Lesson 2 Slides & Student Workbook
Highlighters (Green for addition action clues)
Red pencils (for crossing out "red herrings")
Lesson Breakdown & Pacing
5 Min Warm-Up
10 Min Direct Instruction
10 Min Guided Organizer
5 Min Exit Ticket
1. Fact Mission: Rapid Math Facts
00:00 - 05:00
Review facts within 20 on Slide 2. Speed drill: students write answers on whiteboards. Reinforce part-part-whole relationships.
Teacher Script: "Fact check, detectives! Let's build our brain muscles. Look at slide 2. We have 12 - 4 and 15 - 7. Write the answers on your whiteboards. Show me in 3... 2... 1... Beautiful!"
2. Mini-Lesson: Spotting Red Herrings
05:00 - 15:00
Analyze a word problem on Slide 3. Teach students to look for green action words (join, altogether, in all) which mean addition. Identify "Red Herrings" (extra numbers we do not need, like '3 red wagons').
Teacher Script: "Sometimes word problems trick us with extra clues we don't need! We call these 'Red Herrings'. Look at slide 3: Sam has 115 shiny rocks, 42 dull rocks, and 4 backpacks. We want total rocks. Do we care about backpacks? No! Cross it out in red. Highlight 'altogether' in green because we add!"
3. Guided Case: The Case File Organizer
15:00 - 25:00
Direct students to Workbook Page 2. Read the word problem. Fill out the "Clue Catchers Organizer" as a group. Write key numbers in "Key Facts" and trick numbers in "Red Herring Info".
Teacher Script: "Turn to workbook page 2. Let's read about Agent Fox's marbles. Which numbers match the question? Put those under Key Facts. Put the trick numbers under Red Herrings. Let's write our math equation and solve!"
Differentiation & Intervention Toolkit
Scaffolding (For Struggling Readers) Read aloud. Have them highlight numbers in different colors, or use physical base-ten blocks on their desk to represent the "Key Facts" before writing.
Extension (For Fast Finishers) Have students write their own "Trick Word Problem" on the back of their sheet, including exactly one Red Herring fact. Trade with a partner to solve.
Clue Catchers Slides MATH DETECTIVES UNIT Session 2
CLUE CATCHERS
Learn how to catch "Red Herrings" and highlight key math facts to solve addition word problems up to 200!
Get your green and red highlighters ready! Case Launch • Slide 1/5
MISSION: FACT POWER-UP Warm-Up: 5 Mins
Clue #1: Backwards facts
12 - 4 = ___
Think: What plus 4 equals 12?
Clue #2: Backwards facts
15 - 7 = ___
Think: What plus 7 equals 15?
Clue #3: Doubles Strategy
8 + 8 = ___
Think: Double 8 is...
Clue #4: Near Doubles
8 + 9 = ___
Think: Double 8 plus 1 more!
Write your answers on your whiteboard. Do not shout them out! Slide 2/5
BEWARE OF RED HERRINGS! Mini-Lesson
The Case of the Extra Clues
A Red Herring is extra information in a math problem that has nothing to do with the final question. It is there to try and confuse you!
DETECTIVE TRICK Find the extra information and physically cross it out!
Example Problem
"Agent Fox found 115 blue marbles and 42 green marbles. He also has 4 red backpacks. How many marbles does he have altogether?"
The question asks about marbles. We don't care about backpacks!
If the question doesn't ask about it, cross it out! Slide 3/5
GREEN LIGHT FOR ADDITION Action Keywords
Join
Putting groups together
Altogether
Combined total objects
In All
The complete group
Total
Everything summed up
More
Adding onto a group
When you see these keywords in a problem, highlight them in GREEN! Slide 4/5
CASE FILE #002 Case Challenge
Active Case File
"The museum has 138 gold coins and 44 silver coins. The museum has 6 paintings. How many coins are there in total?"
Which fact is the Red Herring? Which are the Key Facts?
Let's solve together:
Red Herring: 6 paintings
Key Facts: 138 and 44
Equation: 138 + 44 = 182
Excellent work, detectives! Open your workbook and solve the next case! Slide 5/5
Clue Catchers Workbook Math Detectives • Student Case File
Clue Catchers Organizer
Case Log: 002
Detective Name:
__________________________________________
Date:
________________________
Section 1: Fact Power-Up Warm-Up
CLUE #1 12 - 4 = ___
CLUE #2 15 - 7 = ___
CLUE #3 8 + 8 = ___
CLUE #4 8 + 9 = ___
Active Investigation CASE FILE #003
"Agent Fox is sorting through the precinct files. He counts 112 case files on blue paper and 54 case files on yellow paper. He also sees 3 ceramic coffee mugs on his desk. How many case files does Agent Fox have altogether?"
KEY CLUES & NUMBERS
Write down only the numbers you need to solve the case.
RED HERRING / EXTRA INFO
Write down the facts you do NOT need. Draw a line through them!
THE EQUATION
Write your math plan here:
___ + ___ = ___
Final Answer Sentence:
He has _______ files.
DETECTIVE WORKSPACE
Show your horizontal or vertical math strategy here:
Mission 2 Ready for Review Math Detectives Intervention Program • Grade 2
Subtraction Sleuths Teacher Guide Math Detectives • Lesson 3
Subtraction Sleuths
Instructional Guide • Focus: Subtraction Word Problems to 200 & Red Herrings
30 Minutes
Group Size: 5
Core Objectives
Solve 1-step subtraction word problems up to 200.
Filter out extra information ("red herrings") using an organizer.
Use color-coded red/coral keywords to identify subtraction operations.
Required Materials
Lesson 3 Slides & Student Workbook
Highlighters (Red/Coral for subtraction action clues)
Red pencils (for crossing out "red herrings")
Lesson Breakdown & Pacing
5 Min Warm-Up
10 Min Direct Instruction
10 Min Guided Organizer
5 Min Exit Ticket
1. Fact Mission: Rapid Math Facts
00:00 - 05:00
Review mixed subtraction and addition facts within 20 on Slide 2. Speed drill: students write answers on whiteboards. Reinforce finding the missing part.
Teacher Script: "Welcome back, sleuths! Let's power up our detective gears. Look at slide 2. What is 14 - 6? What is 16 - 8? Write them down on your boards. Show me in 3... 2... 1... Amazing quick calculations!"
2. Mini-Lesson: Spotting Red Herrings & Subtraction Clues
05:00 - 15:00
Analyze a word problem on Slide 3. Teach students to look for red/coral subtraction action words (remain, left, fewer, difference) which mean subtraction. Identify and cross out Red Herrings.
Teacher Script: "Now, we have subtraction cases. Look at slide 3. The story says: 'Agent Fox had 185 balloons. 53 popped. He has 12 hats.' Do we care about hats? No! Cross it out in red! Now, highlight the word 'left' in red. 'Left' tells us that we are subtracting a part from the whole. Let's write a subtraction sentence!"
3. Guided Case: The Subtraction Organizer
15:00 - 25:00
Direct students to Workbook Page 3. Read the word problem. Fill out the "Subtraction Sleuths Organizer" as a group. Write key numbers in "Key Facts" and trick numbers in "Red Herring Info".
Teacher Script: "Look at workbook page 3. Let's read about Chief Kelly's badges. Which number is our 'whole'? Which is our 'part'? What is the red herring? Write them in your organizer boxes and show me your subtraction layout!"
Differentiation & Intervention Toolkit
Scaffolding (For Struggling Readers) Have students read the numbers first. Use base-ten blocks. Model how subtracting three-digit numbers requires aligning columns carefully to avoid place-value errors.
Extension (For Fast Finishers) Create a two-step "Sub-Add Case": subtract a red herring first, then add the core numbers. Ask them how this changes our graphic organizer boxes.
Subtraction Sleuths Slides MATH DETECTIVES UNIT Session 3
SUBTRACTION SLEUTHS
Master subtraction word problems up to 200 by catching red herrings and spotting red subtraction clue words!
Get your red and yellow highlighters ready! Case Launch • Slide 1/5
MISSION: FACT POWER-UP Warm-Up: 5 Mins
Clue #1: Backwards facts
14 - 6 = ___
Think: What plus 6 equals 14?
Clue #2: Backwards facts
16 - 8 = ___
Think: This is a double fact! 8 + 8 = 16!
Clue #3: Take Away Strategy
13 - 9 = ___
Think: 13 - 10 is 3, then add 1 back!
Clue #4: Half Strategy
11 - 5 = ___
Think: What plus 5 equals 11?
Write your answers on your whiteboard. Do not shout them out! Slide 2/5
BEWARE OF RED HERRINGS! Mini-Lesson
Red Herrings in Subtraction
We are searching for the whole and the part we subtract. Any other numbers or objects are red herrings!
DETECTIVE TRICK Find the extra information and physically cross it out!
Example Problem
"Agent Fox had 185 balloons for the precinct party. 53 balloon popped. He also bought 12 party hats. How many balloons are left?"
The question asks about balloons. We don't care about party hats!
If the question doesn't ask about it, cross it out! Slide 3/5
RED LIGHT FOR SUBTRACTION Action Keywords
Left
What remains in the group
Fewer
Comparing small to large
Take Away
Removing objects from a group
Difference
The space between two numbers
Remain
Still left after some are gone
When you see these keywords in a problem, highlight them in RED! Slide 4/5
CASE FILE #003 Case Challenge
Active Case File
"Chief Kelly has 165 silver badges in a case. He hands out 43 badges to new deputies. He also has 15 police cars in the garage. How many badges remain in the case?"
Which fact is the Red Herring? Which are the Key Facts?
Let's solve together:
Red Herring: 15 police cars
Key Facts: 165 and 43
Equation: 165 - 43 = 122
Excellent work, detectives! Open your workbook and solve the next case! Slide 5/5
Subtraction Sleuths Workbook Math Detectives • Student Case File
Subtraction Sleuths Organizer
Case Log: 003
Detective Name:
__________________________________________
Date:
________________________
Section 1: Fact Power-Up Warm-Up
CLUE #1 14 - 6 = ___
CLUE #2 16 - 8 = ___
CLUE #3 13 - 9 = ___
CLUE #4 11 - 5 = ___
Active Investigation CASE FILE #004
"Chief Kelly has 165 silver badges locked inside a case. He hands out 43 badges to new deputies. He also has 15 police cars in the garage. How many silver badges remain in the case?"
KEY CLUES & NUMBERS
Write down only the numbers you need to solve the case.
RED HERRING / EXTRA INFO
Write down the facts you do NOT need. Draw a line through them!
THE EQUATION
Write your math plan here:
___ - ___ = ___
Final Answer Sentence:
There are _______ left.
DETECTIVE WORKSPACE
Show your horizontal or vertical math strategy here:
Mission 3 Ready for Review Math Detectives Intervention Program • Grade 2
Grand Finale Teacher Guide Math Detectives • Lesson 4
Grand Finale
Instructional Guide • Focus: Mixed Problems, Numbers to 120, & Fact Mastery
30 Minutes
Group Size: 5
Core Objectives
Solve mixed addition & subtraction word problems up to 200.
Eliminate red herrings and choose appropriate operation.
Write numbers 100-120 with zero reversals.
Required Materials
Lesson 4 Slides & Student Workbook
Green and Red highlighters for student choice
Master Detective printable badges
Lesson Breakdown & Pacing
5 Min Warm-Up
10 Min Mixed Direct
10 Min Final Case Work
5 Min Graduation
1. Fact Mission: Mixed Operations Speed Check
00:00 - 05:00
Run a mixed addition/subtraction facts warm-up using Slide 2. Students solve problems dynamically on their lap boards.
Teacher Script: "Final mission, detectives! Today is our ultimate challenge. Look at slide 2. We have a mix of addition and subtraction. Watch the sign carefully! Write the solution on your board. Reveal in 3... 2... 1... Outstanding speed!"
2. Mini-Lesson: Clue Choice (Add or Subtract?)
05:00 - 15:00
Present the mixed clue strategies on Slide 3 and 4. Teach students to read the problem, cross out the red herrings in red, and determine the operation by locating either a green keyword (addition) or a red keyword (subtraction).
Teacher Script: "On this final case, we aren't told if it is addition or subtraction. We must decide! Look at slide 3. Read carefully. Cross out the trick facts. Is there a green 'join' keyword or a red 'fewer' keyword? Use your detective tools to decide what plan to execute!"
3. Guided Case: The Ultimate Case Sheet
15:00 - 25:00
Have students open Workbook Page 4. Solve the finale word problem together. Then, transition to the "100-120 Reverse-Free Challenge" at the bottom to verify they can write high-level place value numbers without reversals.
Teacher Script: "Open your log to workbook page 4. Complete the mixed organizer case. When you are done, look at the bottom challenge. Write the numbers from 100 to 120 as fast as you can. Keep all your digits facing forward! No swaps allowed!"
Graduation & Next Steps
Scaffolding (For Struggling Writers) If student reverses a digit (e.g., 112 as 121), point to the place value box on slide 3 and ask: "Is this ten and two, or twenty and one?" Have them trace the target digit.
Extension (For Fast Finishers) Instruct fast finishers to write a note to future "novice detectives" explaining the absolute best strategy they learned over these four days.
Grand Finale Slides MATH DETECTIVES UNIT Session 4
THE GRAND FINALE
Let's prove our skills! Solve mixed addition and subtraction word problems, and graduate as Master Math Detectives!
Get ready to graduate from Detective Academy! Graduation Prep • Slide 1/5
FINAL SHOWDOWN: MIXED FACTS Warm-Up: 5 Mins
Clue #1: Addition
9 + 6 = ___
Think: 9 + 1 = 10, then add 5 more!
Clue #2: Subtraction
17 - 8 = ___
Think: 8 + 8 = 16, so what is 17 - 8?
Clue #3: Addition
7 + 8 = ___
Think: Double 7 plus 1 more!
Clue #4: Subtraction
14 - 5 = ___
Think: 14 - 4 = 10, then subtract 1 more!
Watch the sign (+ or -) carefully before you solve! Slide 2/5
THE ULTIMATE CHOICE: + or - ? Mini-Lesson
ADDITION CLUES
Are we joining groups together?
Keywords: altogether, in all, total.
Color code: GREEN LIGHT!
We are combining parts to find the whole.
SUBTRACTION CLUES
Are some items popped, lost, or given away?
Keywords: remain, left, fewer.
Color code: RED LIGHT!
We are taking a part away from the whole.
Scan the problem, cross out the red herrings, and search for the clue words! Slide 3/5
REAL CASE BATTLE Operation Battle
Active Case File
"Detective Chase has 124 silver handcuffs and 51 gold handcuffs. He also has 12 doughnuts in his box. How many handcuffs does he have altogether?"
Step-by-Step Analysis
What is the question asking? Handcuffs
What is the red herring? 12 doughnuts
What is the keyword? altogether
What is the plan? ADD!
Equation: 124 + 51 = 175
Excellent sorting skills! Let's solve the workbook challenge together! Slide 4/5
ACADEMY GRADUATION Mission Accomplished!
CONGRATULATIONS, DETECTIVES!
You successfully completed all cases! You can spot red herrings, write numbers up to 120 backward-free, and solve facts within 20 like real masters!
Finish your final workbook challenge to claim your official badge! Slide 5/5
Grand Finale Workbook Math Detectives • Graduation File
Grand Finale Case Log
Case Log: 004
Detective Name:
__________________________________________
Date:
________________________
The Ultimate Case CASE FILE #005
"Detective Chase has 124 silver handcuffs and 51 gold handcuffs. He also has 12 doughnuts inside a bakery box. How many total handcuffs does Detective Chase have altogether?"
KEY CLUES & NUMBERS
Write only the numbers needed to solve the case.
RED HERRING / EXTRA INFO
Write facts you do NOT need. Draw a line through them!
THE EQUATION
Write your math plan here:
____ [ + or - ] ____ = ____
Final Answer Sentence:
He has _______ handcuffs.
DETECTIVE WORKSPACE
Show your vertical strategy here:
Section 2: Ultimate 100-120 Writing Challenge
Write consecutive numbers from 100 to 120 in the track. Make sure absolutely zero numbers are written backwards!
100
___
___
___
___
___
___
___
___
___
110
___
___
___
___
___
___
___
___
___
120
OFFICIAL GRADUATE BADGE Certified by Academy Instructor: _________________
MASTER DETECTIVE STATUS
