Systems Engineering

Work the numbers

Put large numbers into amounts people can relate to.

A number can be too big to picture. Do a simple calculation to put it on a familiar scale: per person, per household, or per year.

For a national total, divide by the number of people. For a yearly cost, work out what it means per month. Choose a comparison that helps explain the question you are asking, and say what the result measures.

A simple example: U.S. federal debt

Debt is the total owed. The deficit is one year's shortfall. A smaller deficit does not mean the existing debt has been paid off.

The FY2025 figures below work out to about $110,100 in debt per person and $5,200 per person for that year's deficit. Per person includes everyone, including children. It helps us picture the scale; it is not a bill each person receives.

FY2025 snapshot. Per-person amounts use the July 1, 2025 estimate of 341.8 million residents and are rounded to the nearest $100.
Measure	United States	Per person
Annual deficit Shortfall during FY2025	United States$1.7754 trillion	Per personAbout $5,200for that year
Total federal debt Total on September 30, 2025	United States$37.6376 trillion	Per personAbout $110,100accumulated at that date

The calculation

Annual deficit: $1.7754 trillion ÷ 341.8 million people ≈ $5,200 per person for FY2025.

Total debt: $37.637553 trillion ÷ 341.8 million people ≈ $110,100 per person at year-end.

For a household of six

The federal debt works out to about $660,000 for a family of six. That is enough money to buy a house.

If that were your mortgage at a 7% annual rate, the interest alone would be $3,850 a month, before paying back any of the loan.

Is this a housing crisis—or a debt crisis?

The government has already borrowed the equivalent of a house for a family of six. Your family must still buy its own home and help pay interest on that public debt. That is the double burden: your housing costs, plus the cost of past government borrowing.

Discussion questions

For individual reflection or classroom discussion. These questions are not graded.

What does the per-person amount help you understand that the national total does not?
What is the difference between total debt and one year's deficit?
For a household of six, how does the monthly interest comparison help you picture the scale?

Principles

Distinguish an amount at a point in time from a rate over time, and use consistent units.
A continuing shortfall accumulates; a one-time asset sale cannot indefinitely fund recurring expenses.

Why this matters

We must do the arithmetic before judging a claim.
Check the units and time period, distinguish totals from changes over time, and use per-person or household comparisons to show scale.
These comparisons are not individual bills.

Learn more & discuss

Another example: what does each home cost?

Imagine a low-income housing project that will provide homes for 62 families. Its total budget is $49.6 million.

$49,600,000 ÷ 62 homes = $800,000 per home.

The total sounds like a big project. The cost per home gives us a number we can compare. At $800,000 each, ask: could the same money provide suitable housing for more families another way?

If an equally suitable option cost $400,000 per home, the same budget could provide 124 homes instead of 62. Check that both options include the same costs and meet the same needs.

High costs can hide private gain

If the price is far above comparable options and nobody can explain the difference, ask where the extra money goes. Inflated contracts can create room for favoritism and kickbacks.

For example, a decision maker could steer an overpriced contract to a cousin's company. Part of the extra money could come back as cash, a paid vacation, or a car. Money intended to house families would instead benefit the people arranging the deal.

Check competing bids, who owns the contractor, invoices, and any benefits received by the decision makers. A high price is a warning to investigate; establishing fraud requires evidence.

Use the other principles

Opportunity cost: what you give up. What other housing could this money provide? Compare building, buying existing homes, repairs, or rent assistance.
Defining the system. What does the budget include: land, buildings, roads, utilities, fees, or future upkeep? Compare like with like.
Measure the outcome. Count families actually housed, for how long, and at what cost.
Motivation and conflicts of interest. Who benefits from awarding the contract, and are there personal connections or private rewards?

Discussion questions

What other housing could the same budget provide?
What costs must be included to compare the options fairly?
If the price is far above comparable options, what records would help explain the difference or reveal favoritism and kickbacks?

Reference: HUD Inspector General: contracting fraud and kickbacks.

Rate this foundation

1.00 / 5 · 0 user ratings

References

Check your understanding

How would you turn total national debt into an amount per person?

Multiply the total debt by the population.

Divide the total debt by the population and label the date of the debt figure.

Use the annual deficit as though it were the total debt.

Create an account to check your answer and save your progress.

Create an account Sign in