Missing Money Slides Case File #01
The Missing Money
Uncovering the Truth Behind Gross vs. Net Income
Payroll Detective Agency
The Mystery Check
Global Tech Solutions
123 Career Blvd, Future City, USA
#0001234
Date: 01/15/2026
PAY TO THE ORDER OF: Jordan Rivera
Seven Hundred Eighty and 00/100
FOR: Earnings for Pay Period 1/1 - 1/15
Amount
$780.00
The Discrepancy
Jordan worked 50 hours at $20 per hour.
50 hrs × $20/hr = $1,000.00
"Where did the other $220.00 go?"
The Detective's Glossary
Gross Pay
The total amount of money you earned before any taxes or deductions are taken out.
Hours Worked × Hourly Rate = Gross Pay
Net Pay
The amount you actually take home after all deductions. This is your "spendable" income.
Gross Pay - Deductions = Net Pay
The Golden Rule of Paychecks
In general, your Take-Home Pay will be approximately...
70% - 80%
...of your Gross Income.
If you earn
$1,000
You keep
~$750
Case Debrief
"Why is it dangerous to budget based on your Gross Pay instead of your Net Pay?"
Consider: Rent, car payments, and groceries... Can you pay for them with money that never hits your bank account?
Mystery Check Worksheet The Missing Money
Case File #01: Gross vs. Net Income
Agent Name:
Date:
Part 1: The Mystery Check
Subject: Jordan RiveraReport: Jordan worked 50 hours last pay period at a rate of $20.00 per hour. When they checked their bank account, the deposit was only $780.00.
Calculate the Expected Pay (Gross):
50 hours × $20/hr = $__________
Identify the "Missing" Amount:
Expected - Actual ($780) = $__________
Theorize: Where do you think that "missing" money went? List three possibilities.
1
2
3
Part 2: Calculation Station
Assume a standard 25% total deduction rate for these scenarios (Net Pay = 75% of Gross).
Scenario Calculation (Gross) Gross Pay Estimated Net (× 0.75) Alex: 40 hrs @ $15/hr 40 × 15 $__________ $__________ Sam: 35 hrs @ $22/hr 35 × 22 $__________ $__________ Casey: 45 hrs @ $30/hr* Overtime! (40×30) + (5×45) $__________ $__________
*Note: Overtime is typically 1.5× hourly rate for hours over 40.
Part 3: The Reality Check
1. Define the difference between Gross Income and Net Income in your own words.
2. If you are applying for a job that pays $50,000 per year, why is it a mistake to budget your life as if you have $4,166 per month ($50k ÷ 12)? What should you actually budget for?
Payroll Detective Agency | Field Worksheet
Case #01-A
Gross vs Net Teacher Guide Teacher Facilitation Guide
Lesson 1: The Missing Money (Gross vs. Net)
Version 1.0 | 45-60 MIN
Lesson Objective
Students will understand the functional difference between gross and net income, calculate earnings based on hourly rates, and apply a realistic "take-home" percentage to set accurate financial expectations for their future careers.
Key Terms
Gross Income
Net Income
Deductions
Overtime (1.5x)
Instructional Sequence
1
The Hook: Mystery Check (10 mins)
Display **Slide 2**. Ask students to calculate Jordan's pay ($20/hr × 50 hrs). When they realize it's $1,000, ask: "Why did Jordan only get $780? Where is the 'missing' $220?"
Teacher Tip: Do not give the answers yet. Let them brainstorm wild theories (stolen money, hidden fees, banking errors) to build curiosity.
2
Defining the Terms (15 mins)
Transition to **Slides 3-4**. Define Gross vs. Net clearly. Use the "Golden Rule" (70-80% rule) as a mental shortcut. Explain that net pay is the only number that matters for building a budget.
3
Worksheet Application (20 mins)
Distribute the **Mystery Check Worksheet**. Students complete calculations for Alex, Sam, and Casey.
ANSWER KEY (Part 2):
4
Debrief & Closing (10 mins)
Use **Slide 5** to facilitate a discussion on budgeting. Key takeaway: "Gross income is your potential; Net income is your reality."
Differentiation & Support
For Students Needing Support:
Provide a multiplication chart and allow the use of calculators. Focus on the 75% estimation rather than precise percentage math if needed.
For Advanced Learners:
Challenge them to research 'Progressive Tax Brackets' and explain why the 75% rule might change if they earned $200,000 instead of $50,000.
FICA Files Slides Case File #02
The FICA Files
Mandatory Deductions & The Social Safety Net
Statutory Investigation Unit
The Acronym Decoded
F.I.C.A.
Federal Insurance Contributions Act
This is a mandatory federal payroll tax. Both you and your employer pay into it to fund federal programs.
You don't get a choice to opt out of FICA.
Social Security
Provides income for retirees, the disabled, and survivors of deceased workers.
6.2%
Medicare
Provides health insurance for Americans aged 65 and older and younger people with disabilities.
1.45%
Where Does the Money Go?
35% Payroll Taxes
Other Revenue
The Revenue Mix
Approximately one-third of all federal revenue comes from payroll taxes (FICA).
Social Security is the largest federal program.
Current workers pay for current retirees.
It's a "pay-it-forward" system.
Doing the Math
Gross Monthly Pay
$4,000.00
SS
Social Security (6.2%)
$4,000 × 0.062
$248.00
MC
Medicare (1.45%)
$4,000 × 0.0145
$58.00
Total FICA Deduction
-$306.00
Mandatory Deductions Worksheet The FICA Files
Case File #02: Statutory Deductions & Tax Pots
Detective:
Payroll Period:
Part 1: The Definition Brief
What is FICA?
FICA stands for the Federal Insurance Contributions Act. It is a mandatory payroll tax that funds Social Security and Medicare.
The Breakdown
Social Security: 6.2%
Medicare: 1.45%
Total FICA: 7.65%
Part 2: Calculation Lab
Calculate the specific FICA deductions for the following monthly gross salaries. Use the rates: SS = 6.2% (0.062) and MC = 1.45% (0.0145) .
Monthly Gross Social Security (6.2%) Medicare (1.45%) Total FICA $2,500.00 $__________ $__________ $__________ $5,200.00 $__________ $__________ $__________ $8,333.33 $__________ $__________ $__________
Part 3: The Employer Match
Did you know? You only pay HALF of your FICA taxes. Your employer is legally required to match your contribution dollar-for-dollar.
If your paycheck shows a total of $350.00 taken out for FICA today...
How much total money is actually sent to the government on your behalf?
Why do you think the government makes employers pay this too?
Part 4: The Social Contract
You are paying Social Security for people who are retired now . When you retire in 50 years, younger workers will pay for your check. This is called the 'Social Safety Net'.
In your opinion, is this a fair system? Why or why not?
FICA Investigation Unit | Case #02-B
Tax Pot Teacher Guide Teacher Facilitation Guide
Lesson 2: The FICA Files (Statutory Deductions)
Version 1.0 | 45-60 MIN
Lesson Objective
Students will identify Social Security and Medicare as mandatory federal deductions, calculate their specific financial impact using percentage-based math, and analyze the 'social contract' nature of the US payroll system.
Key Terms
FICA
Social Security (6.2%)
Medicare (1.45%)
Employer Match
Instructional Sequence
1
Hook: The National Pot (10 mins)
Display **Slide 3**. Ask students: "Where does the government get its money?" Show that 1/3 comes directly from their future paychecks. Explain that this money isn't just "lost"—it's an insurance contribution for the future.
2
FICA Anatomy (15 mins)
Use **Slide 2** to break down the acronym. Emphasize that Social Security is about *income* and Medicare is about *healthcare*.
Teacher Tip: Ask if anyone has grandparents receiving Social Security. This helps ground the abstract concept in real-world family impact.
3
Calculation Lab (20 mins)
Distribute the **Mandatory Deductions Worksheet**. Walk through the first example on **Slide 4** together before they start.
ANSWER KEY (Part 2):
4
The Social Contract Discussion (10 mins)
Review the "Employer Match" concept. Explain that hiring an employee costs a company MORE than just their salary (salary + 7.65% FICA match + benefits). Discuss the "fairness" of the social safety net.
Common Misconceptions
"Social Security is like a savings account for me." - NO. It is a transfer system from current workers to current retirees. The money you pay today is spent today."I can opt out if I promise to save for my own retirement." - NO. It is mandatory for almost all employees in the US (with very few exceptions like certain government or religious roles). W-4 Workshop Slides Case File #03
Navigating the W-4
Controlling Your Federal Withholding
Internal Revenue Workshop
The Employee's Remote Control
Form W-4 tells your employer how much federal income tax to take out of your paycheck.
The Golden Question
"Do I want more money now, or a big refund later?"
Key Factors on the W-4:
1
Filing Status
Single, Married, Head of Household
2
Dependents
Children or others you support financially
3
Other Income
Extra jobs or side hustles
The "Tax Refund" Surprise
Under-Withholding
You took home too much money during the year. Now you OWE the IRS money in April.
Over-Withholding
The IRS took too much money. You get a big REFUND in April. (Essentially an interest-free loan to the govt!)
"The goal is a 'Breaking Even'—having exactly enough taken out."
Simulation Workshop
We are going to simulate three different lives. Watch how your "Paycheck Reality" changes based on the boxes you check on the W-4.
The Single Grad
Zero dependents, one job.
The Parent
Two kids, Head of Household.
The Side-Hustler
Full-time job + Freelance income.
Withholding Simulation Worksheet Withholding Simulation
Case File #03: The W-4 Workshop
Student Name:
Part 1: Scenario Assignments
Scenario A
Alex: The Recent Grad
Alex just graduated and started their first job at an accounting firm. Alex is Single , has no children , and only has one job .
GOAL: Ensure enough tax is withheld to avoid owing at the end of the year.
Scenario B
Morgan: The Single Parent
Morgan works as a nurse. Morgan is Single but provides more than half the support for two children (ages 4 and 7).
GOAL: Claim child tax credits to increase take-home pay for family needs.
Part 2: Simulated Form W-4
Step 1: Personal Information
Filing Status (Check One)
Single
Married Filing Jointly
Head of Household
Step 2: Multiple Jobs or Spouse Works
Complete this step if you hold more than one job at a time.
Check here if you have only two jobs total.
Step 3: Claim Dependents
Number of qualifying children under age 17 × $2,000
$
Step 4: Other Adjustments (Optional)
(a) Other Income (not from jobs)
(c) Extra Withholding (per pay period)
Part 3: Prediction & Impact
Analysis Question:
If Morgan (Scenario B) accidentally checked "Single" instead of "Head of Household" and forgot to claim their 2 children in Step 3, what would happen to their monthly take-home pay? Would it go up or down? Explain why.
Official Training Document | W-4 Simulation 2026
W-4 Facilitation Guide Teacher Facilitation Guide
Lesson 3: Form W-4 Workshop (Navigating Withholding)
IRS SIMULATION | 60 MIN
Lesson Objective
Students will accurately complete a simulated Form W-4 based on provided life scenarios and explain how filing status, dependents, and extra income affect the amount of federal income tax withheld from a paycheck.
Workshop Materials
W-4 Workshop Slides
Withholding Worksheet
Calculator
Instructional Sequence
1
The "Remote Control" Analogy (10 mins)
Use **Slide 2**. Explain that the W-4 is how an employee tells the company how much tax to "hold back." If they don't hold back enough, the IRS will bill them in April. If they hold back too much, the IRS sends a refund (which is money the student could have used for rent/food during the year).
2
Status & Dependents Walkthrough (15 mins)
Explain Step 1 and Step 3 on the W-4. **Single** = Higher tax rate. **Head of Household** = Lower tax rate (reserved for those with dependents). **Step 3** = Each child reduces the amount of tax withheld (credits).
3
Simulation Workshop (25 mins)
Assign students to either Scenario A or B on the **Withholding Simulation Worksheet**.
EXPECTED RESULTS: Scenario A: Single status. Step 3 = $0. Step 4 = $0.Scenario B: Head of Household. Step 3 = $4,000 (2 kids × $2k).Analysis Answer: Morgan's take-home pay would DROP significantly. Single status and no dependents would make the employer withhold MORE tax, leaving Morgan with less cash for monthly bills.
4
The "April Surprise" Debrief (10 mins)
Ask: "Who wants a $3,000 refund in April?" Most will raise hands. Then ask: "Who wants $250 extra in every monthly paycheck for rent?" Discuss which is better for a first-year grad living paycheck-to-paycheck.
Workshop Pro-Tips
Side Hustles: Remind students that DoorDash/Uber don't withhold tax automatically. They should use Step 4(a) on their "W-2 Job" W-4 to account for that extra income so they aren't surprised by a tax bill.Updates: You can change your W-4 at any time! If you have a baby or get married in June, you should file a new W-4 that week. State Line Shift Slides Case File #04
State Line Shift
Geography & Your Take-Home Pay
Regional Economic Analysis
The Geographic Gap
Imagine you land a job offer for $100,000 per year. Is your take-home pay the same everywhere?
Austin, TX
State Income Tax: 0%
Est. Take Home
$77,200
San Francisco, CA
State Income Tax: ~9.3%
Est. Take Home
$69,500
The Cost of Living Equation
Lower taxes don't always mean more wealth.
States without income tax often have higher...
Property Taxes
Sales Taxes
Gas/Gasoline Fees
Wealth ≠ Take Home
"Wealth is what you keep after you pay for your taxes AND your life."
The "No Tax" States
Alaska
Florida
Nevada
South Dakota
Tennessee
Texas
Washington
Wyoming
New Hampshire*
*NH tax interest and dividends only, though this is being phased out.
Geography and Taxes Worksheet Geography and Taxes
Case File #04: The Regional Reality Check
Analyst:
Part 1: The Take-Home Comparison
Complete the table below for a salary of $60,000 per year . Assume federal taxes (FICA + Federal Income Tax) are a flat 20% ($12,000) for this exercise.
State Location State Tax Rate State Tax Amount Final Take Home Seattle, WA 0% $0.00 $48,000.00 New York, NY 6.0%* $__________ $__________ Chicago, IL 4.95% $__________ $__________ Phoenix, AZ 2.5% $__________ $__________
*Simplified rate for New York State (excludes local NYC city tax for this exercise).
Part 2: The Cost of Living Adjustment
Scenario Analysis: Seattle vs. Phoenix
You have two offers for $60,000. Seattle has 0% state tax . Phoenix has 2.5% state tax . However, look at the median rent prices:
Seattle Rent (Annual)
$24,000
Phoenix Rent (Annual)
$18,000
Calculate the "Disposable Income" (Take Home from Part 1 minus Rent):
Seattle: $48,000 - $24k = $__________
Phoenix: $__________ - $18k = $__________
Part 3: The Verdict
1. Based on your calculation above, which city actually leaves you with more money for food, travel, and savings? Does the 0% state tax in Washington make up for the higher rent?
2. If you were looking for a job today, would you prioritize a state with no income tax? Why or why not?
Regional Economic Analysis | Case #04-C
Tax Comparison Teacher Guide Teacher Facilitation Guide
Lesson 4: State Line Shift (Geographic Tax Burdens)
VERSION 1.0 | 45-60 MIN
Lesson Objective
Students will compare state income tax rates across the US, calculate the impact of these taxes on a standard salary, and evaluate how cost-of-living factors (like rent) can offset the benefits of low-tax regions.
Key Terms
State Income Tax
Cost of Living (COL)
Disposable Income
Tax Reciprocity
Instructional Sequence
1
The Austin vs. SF Hook (10 mins)
Display **Slide 2**. Ask: "If you could pick one job for $100k, which city would you choose?" Most will pick Austin for the tax savings. Ask: "Is it really that simple?"
2
Tax Mapping (15 mins)
Use **Slides 3-4** to discuss the "No Tax" states. Explain that while these states don't tax income, they often have higher sales or property taxes to fund schools and roads.
3
Calculation Lab (20 mins)
Students complete the **Geography and Taxes Worksheet**.
ANSWER KEY (Part 1): ANSWER KEY (Part 2):
4
The Verdict Debrief (10 mins)
Discuss Part 2. Students should realize that Phoenix actually leaves them with MORE money, despite having a state tax, because the rent is lower. Discuss other factors: quality of life, proximity to family, weather.
Discussion Starters
"If a state has 0% income tax, where do they get money for fire departments and public schools?"
"Would you move to a state you hate just to save 5% on taxes?"
"Why might a company choose to open an office in a high-tax state like California instead of a no-tax state like Wyoming?"
Payroll Audit Slides Mastery Challenge
Payroll Audit
Protecting Your Earnings from Human Error
Fraud Prevention Bureau
The Auditor's Mindset
"Payroll software is only as good as the person entering the data."
Common Errors
Wrong hourly rate entered
Overtime hours missed
Math errors in FICA calculation
Old W-4 information being used
The Rule of Law
It is your responsibility to check your paystub every single period. Once the money is gone, it can be hard to get back.
Case Brief: "Find the Fraud"
We have three paystubs from "FastFix Automotive." Each employee thinks something is wrong. Your job: **Find the error** and **calculate the correct Net Pay**.
Stub #1: "Missing OT"
Did they count the extra Saturday shift?
Stub #2: "The Tax Glitch"
Is the FICA percentage correct?
Stub #3: "W-4 Ignore"
Did they process the new dependent?
The Audit Checklist
1
Verify Gross Pay: Hours × Rate (Check for OT)
2
Verify Statutory Taxes: FICA (7.65%)
3
Verify Voluntary Deductions: Insurance, 401k
4
The Bottom Line: Gross - Deductions = Net
READY?
Grab your "Fraud Finder" worksheet. You have 20 minutes to clear the cases.
START THE CLOCK
Fraud Finder Worksheet Fraud Finder Challenge
Case File #05: Final Payroll Audit
Head Auditor:
Mission Briefing:
Below are two suspicious paystubs from "FastFix Automotive." Each has at least one error that is costing the employee money. Identify the error(s) and calculate what the Net Pay should have been.
1
Case #01: Taylor (The Overtime Oversight)
FASTFIX AUTOMOTIVE
PAYEE: Taylor Smith
ID: #TS-902
PAY DATE: 02/01/2026
PERIOD: 01/15 - 01/30
EARNINGS
Regular (40 hrs @ $20/hr) $800.00
Overtime (8 hrs @ $20/hr) $160.00
TOTAL GROSS $960.00
DEDUCTIONS
FICA Tax (7.65%) $73.44
Federal Withholding $90.00
TOTAL NET PAY $796.56
The Error Found:
Corrected Net Pay Calculation:
2
Case #02: Jordan (The FICA Glitch)
FASTFIX AUTOMOTIVE
PAYEE: Jordan Lee
PAY DATE: 02/01/2026
EARNINGS
Salary (Flat Rate) $2,000.00
TOTAL GROSS $2,000.00
DEDUCTIONS
FICA Tax (10%) $200.00
Federal Withholding $250.00
TOTAL NET PAY $1,550.00
The Error Found:
Corrected Net Pay Calculation:
OFFICIAL AUDIT DOC #FF-001
PROPERTY OF PAYROLL DETECTIVE AGENCY
Audit Answer Key Audit Answer Key
Lesson 5: Payroll Audit Challenge (Final Assessment)
CONFIDENTIAL | TEACHER ONLY
Grading Standard
Students should be awarded full points only if they identify both the error type and the correct mathematical adjustment.
Found Error
40%
Correct Math
40%
Explanation
20%
1
Case #01: Taylor Smith
The Error
The Overtime (OT) rate is calculated at 1.0x instead of 1.5x.
The stub shows 8 hrs @ $20 = $160. It should be 8 hrs @ $30 = $240.
Corrected Calculation
New Gross: $800 (Reg) + $240 (OT) = $1,040.00
New FICA (7.65%): $79.56
Fed Withholding (Assumed same): $90.00
Corrected Net Pay: $870.44
2
Case #02: Jordan Lee
The Error
Incorrect FICA Percentage used.
The stub uses 10% ($200) for FICA. The statutory rate is 7.65%.
Corrected Calculation
Gross: $2,000.00
Correct FICA (7.65%): $153.00
Fed Withholding: $250.00
Corrected Net Pay: $1,597.00
Internal Audit Key | 12th Grade Workplace Rights
